Lightning Component - Picklist Field with Ability to write free text

I need to override standard Create and Edit Actions on Account object with Lightning Component. Is there a way or a type of field that we could cover the following requirement?
Have a field with some predifined values but letting user if he wants to enter free text. I would actually like something like Subject field on Task object but i cannot find any way to implement it. Any ideas please ?

Example: I have a picklist field for Citizenship that has some values for Countries (England, Germany, France, …etc…). But i want to let user enter his own value (for example: German). i have tried using the following but without success:

<!--05/09/2019 George Galaios: Code for Iteration Picklist: Citizenship -->
                        <lightning:select aura:id="accCitizenship" label="{!$Label.c.ea_citizenship}" value="{!v.accountRecord.ea_Citizenship__c}" disabled="{!and(v.noExtraPermission, v.noPermAndCleansed)}" class="slds-size--1-of-2 slds-p-horizontal_x-small">
                            <aura:iteration items="{!v.ea_Citizenship_Values}" var="item">
                                <option value="{!item}" selected="{!item==v.accountRecord.ea_Citizenship__c}">{!item}</option>
                            </aura:iteration>
                        </lightning:select>                
                        <!-- End of Code for Iteration -->

15/11/2020 UPDATE: I update my question with my solution, in order to help someone with the same issue.

Component

<!--27/10/2019 George Galaios: This component is created in order to cover Citizenship fields. Those fields are not restricted picklists, so it is needed to accept either values from Picklists or Free Text! -->
<!--27/10/2019 George Galaios: Define the appopriate Attributes.-->
<aura:component controller="ea_PickListController">
    <aura:attribute name="objectName" type="String" default="Account"/>
    <aura:attribute name="fieldName" type="String" default="ea_Citizenship__c"/>
    <aura:attribute name="selectRecordId" type="String"/>
    <aura:attribute name="selectRecordName" type="String"/>
    <aura:attribute name="Label" type="String" default="{!$Label.c.ea_citizenship}"/>
    <aura:attribute name="picklistValues" type="String[]"/>
    <aura:attribute name="allListValues" type="String[]"/>
    <aura:attribute name="required" type="Boolean" default="false"/>
    <aura:attribute name="iconName" type="String" default="utility:identity"/>
    <aura:attribute name="LoadingText" type="Boolean" default="false"/>
    <aura:attribute name="readonly" type="Boolean" default="false"/>
    <aura:attribute name="helpText" type="String" default="Επιλέξτε μία χώρα από την λιστα είτε πληκτρολογήστε μία τιμή της επιλογής σας"/>
    
    <!--27/10/2019 George Galaios: If focus goes out, call closeDropDown Controller function-->
    <div onfocusout="{!c.closeDropDown}">         
        <div class="slds-combobox_container slds-size--1-of-1 slds-p-horizontal_x-small">
            
            <div class="slds-size--1-of-1 slds-p-horizontal_x-small slds-combobox slds-dropdown-trigger slds-dropdown-trigger_click" aura:id="resultBox" aria-expanded="false" aria-haspopup="listbox" role="combobox">
                <div class="slds-form-element__control" role="none">
                    <aura:if isTrue="{!v.readonly}">
                        
                        <!--27/10/2019 George Galaios: Input Field for Citizenship. When user typing, call searchField Controller function-->                    
                        <lightning:input required="{!v.required}" disabled="{!v.readonly}" aura:id="userinput" label="{!v.Label}" name="searchText" value="{!v.selectRecordName}" fieldLevelHelp="{!v.helpText}" class="leftspace"/>
                        
                        <aura:set attribute = "else">
                            <!--27/10/2019 George Galaios: Input Field for Citizenship. When user typing, call searchField Controller function-->                    
                            <lightning:input required="{!v.required}" disabled="{!v.readonly}" aura:id="userinput" label="{!v.Label}" name="searchText" onchange="{!c.searchField}" onclick="{!c.getPickListValues}" value="{!v.selectRecordName}" isLoading="{!v.LoadingText}" type="search" fieldLevelHelp="{!v.helpText}" class="leftspace"/></aura:set>
                        
                    </aura:if>
                    
                </div>
                
                <!--27/10/2019 George Galaios: Second part display result -->
                <div id="listbox-id-1" class="slds-dropdown slds-dropdown_length-with-icon-7 slds-dropdown_fluid" role="listbox">
                    <ul class="slds-listbox slds-listbox_vertical" role="presentation" >
                        <aura:iteration items="{!v.picklistValues}" var="serecord" indexVar="hdtv">
                            <li role="presentation" class="slds-listbox__item">
                                <!--27/10/2019 George Galaios: Show the list of values that match user's typed criteria. Onmousedown call setSelectedRecord controller function  -->
                                <div data-name="{!serecord}" onmousedown="{!c.setSelectedRecord}"  class="slds-media slds-listbox__option slds-listbox__option_entity slds-listbox__option_has-meta" role="option">
                                    <span class="slds-media__figure">
                                        <span class="slds-icon_container slds-icon-standard-account">
                                            <!--27/10/2019 George Galaios: Show icon on the left of results displayed  -->                                            
                                            <lightning:icon iconName="{!v.iconName}" class="slds-icon slds-icon slds-icon_small slds-icon-text-default" size="x-small"/>
                                        </span>
                                    </span>
                                    <span class="slds-media__body">
                                        <!--27/10/2019 George Galaios: Display Countries Names  -->
                                        <span class="slds-listbox__option-text slds-listbox__option-text_entity">{!serecord}</span>
                                    </span>
                                </div>
                            </li>
                        </aura:iteration>
                        
                        <!--27/10/2019 George Galaios: If loading, show the appropriate message on the screen  -->
                        <aura:if isTrue="{!v.LoadingText}">
                            Loading...
                        </aura:if>
                    </ul>
                </div>
            </div>                                          
        </div>
    </div>           
</aura:component>

Controller

//ggalaios @ 27/10/2019 
//Lightning Component for Citizenships fields of Account
//Component Controller

({
    //When clicking on the component it calls Apex function that fetches the values of the picklist field that is given
    getPickListValues : function(component) {
        //Check if field is in ReadOnly mode and confirm that it does not already have a value
        if ((component.get("v.readonly") == false) && ((component.get("v.selectRecordName") == "" || component.get("v.selectRecordName") == undefined || component.get("v.selectRecordName") == null))) {
            component.set("v.LoadingText", true);
            var action = component.get("c.getPickListValuesIntoList");
            action.setParams({
                //set the appropriate params
                "objectType": component.get("v.objectName"),
                "selectedField": component.get("v.fieldName")
            });
            action.setCallback(this, function(response) {
                var list = response.getReturnValue();
                component.set("v.picklistValues", list);
                component.set("v.allListValues", list);
                component.set("v.LoadingText", false);
                var resultBox = component.find('resultBox');
                $A.util.addClass(resultBox, 'slds-is-open');
                //console.log('return value: ' +response.getReturnValue());
            })
            $A.enqueueAction(action);
        }
    },
    
    //Function called while user typing on input field
    searchField : function(component, event, helper) {
        //Capitalize input
        component.set("v.LoadingText", true);
        var currentText = helper.RemoveAccentsAndCapitalize(event.getSource().get("v.value"));
        //Capitalize Component attribute
        component.set("v.selectRecordName", currentText);
        var resultBox = component.find('resultBox');
        //if length of text typed by user > 0 show resultBox, else not show it and assign again PickListValues Attriute the whole list of values
        if(currentText.length > 0) {
            $A.util.addClass(resultBox, 'slds-is-open');
            //Call Apex Class to return the results while user is typing
            //console.log('Just before calling Apex... current Text is: ' +currentText);
            var action = component.get("c.getSearchList");
            action.setParams({
                "citizenshipList" : component.get("v.allListValues"),
                "value" : currentText
            });
            action.setCallback(this, function(response){
                var STATE = response.getState();
                if(STATE === "SUCCESS") {
                    //console.log('from function is returned...: ' +response.getReturnValue());
                    component.set("v.picklistValues", response.getReturnValue());
                    component.set("v.LoadingText", false);
                    if(component.get("v.picklistValues").length == 0) {
                        $A.util.removeClass(resultBox, 'slds-is-open');
                    }
                }
                else if (state === "ERROR") {
                    var errors = response.getError();
                    if (errors) {
                        if (errors[0] && errors[0].message) {
                            console.log("Error message: " + 
                                        errors[0].message);
                        }
                    } else {
                        console.log("Unknown error");
                    }
                }
            });
            $A.enqueueAction(action);
        }
        else {
            component.set("v.LoadingText", true);
            //console.log('case is currentText is zero length');
            var action = component.get("c.getPickListValuesIntoList");
            action.setParams({
                //set the appropriate params
                "objectType": component.get("v.objectName"),
                "selectedField": component.get("v.fieldName")
            });
            action.setCallback(this, function(response) {
                var list = response.getReturnValue();
                component.set("v.picklistValues", list);
                component.set("v.allListValues", list);
                var resultBox = component.find('resultBox');
                component.set("v.LoadingText", false);
                $A.util.addClass(resultBox, 'slds-is-open');
            })
            $A.enqueueAction(action);
        }
    },
    
    //when user clicks (X) button, set the appropriate Attributes blank.
    resetData : function(component, event, helper) {
        component.set("v.LoadingText", true);
        component.set("v.selectRecordName", "");
        component.find('userinput').set("v.readonly", false);
        component.set("v.LoadingText", false);
    },
    
    //When user selects a record, set it as selected
    setSelectedRecord : function(component, event, helper) {
        var currentText = event.currentTarget.id;
        var resultBox = component.find('resultBox');
        $A.util.removeClass(resultBox, 'slds-is-open');
        component.set("v.selectRecordName", event.currentTarget.dataset.name);
    }, 
    
    //Function when user clicks outside Component to close the dropdown list
    closeDropDown : function(component, event, helper) {
        var resultBox = component.find('resultBox');
        $A.util.removeClass(resultBox, 'slds-is-open');
        component.set("v.LoadingText", false);
    },
    
    
})

Helper

({
    RemoveAccentsAndCapitalize: function(strAccents) {
        var strAccents = strAccents.split('');
        var strAccentsOut = new Array();
        var strAccentsLen = strAccents.length;
        var accents = 'ÀÁÂÃÄÅàáâãäåÒÓÔÕÕÖØòóôõöøÈÉÊËèéêëðÇçÐÌÍÎÏìíîïÙÚÛÜùúûüÑñŠšŸÿýŽžάέήύόύϋΰίϊΐώΆΈΉΎΌΆΎΊΏ';
        var accentsOut = "AAAAAAaaaaaaOOOOOOOooooooEEEEeeeeeCcDIIIIiiiiUUUUuuuuNnSsYyyZzαεηυουϋϋιϊϊωαεηυοαυιω";
        for (var y = 0; y < strAccentsLen; y++) {
            if (accents.indexOf(strAccents[y]) != -1) {
                strAccentsOut[y] = accentsOut.substr(accents.indexOf(strAccents[y]), 1);
            } else
                strAccentsOut[y] = strAccents[y];
        }
        strAccentsOut = strAccentsOut.join('');
        return strAccentsOut.toUpperCase(); //@ggalaios return string also capitalized
    },
})

Style

.THIS .slds-leftpad{
    padding-left: 2rem;
}
.THIS .iconheight{
    top: 65%;
}

.THIS .leftspace input {
    padding-left:2rem;
}

Apex Class Controller

public class ea_PickListController {
    @AuraEnabled
    //15/09/2019: George Galaios: Method to get Picklist values
    public static List<String> getPickListValuesIntoList(String objectType, String selectedField){
        List<String> pickListValuesList = new List<String>();
        Schema.SObjectType convertToObj = Schema.getGlobalDescribe().get(objectType);
        Schema.DescribeSObjectResult res = convertToObj.getDescribe();
        Schema.DescribeFieldResult fieldResult = res.fields.getMap().get(selectedField).getDescribe();
        List<Schema.PicklistEntry> ple = fieldResult.getPicklistValues();
        //27/10/2019: ggalaios: Check if SelectedField is different than Citizenships. Because in Citizenships we do not want the Choice "Please Select"
        if ((selectedField != 'ea_Citizenship__c') && (selectedField != 'ea_Citizenship2__c') && (selectedField != 'ea_Profession__c')) {
            pickListValuesList.add('--Παρακαλώ Επιλέξτε--');
        }
        for( Schema.PicklistEntry pickListVal : ple){
            pickListValuesList.add(pickListVal.getLabel());
        }     
        return pickListValuesList;
    }
    
    @AuraEnabled
    //27/10/2019 George Galaios: This method is called while user is typing (searching for Citizenship)
    public static List<String> getSearchList(List<String> citizenshipList, String value) {
        //Initiate the list that is going to be returned
        List<String> searchResultList = new List<String>();
        try {
            //for every item of the list check if what user has typed is contained in the List of Citizenships
            for (Integer i=0; i<citizenshipList.size(); i++) {
                if (citizenshipList[i].contains(value)) {
                    searchResultList.add(citizenshipList[i]);
                }
            }
        } catch (Exception e) {
            system.debug('exception caught: ' +e.getMessage());
        }
        return searchResultList;
    }
}

Apex Class Controller Test

@isTest
//Test class for ea_PickListController Apex Class
public class ea_PickListControllerTest {
    @isTest Public static void getPickListValuesIntoListTest() {
        ea_PickListController.getPickListValuesIntoList('Account', 'ea_CustomerType__c');
    }
    
    //Test getSearchList method
    @isTest public static void getSearchListTest() {
        List<String> testList = new List<String>();
        testList.add('ΑΓΓΛΙΑ');
        testList.add('ΕΛΛΑΔΑ');
        testList.add('ΗΝΩΜΕΝΕΣ ΠΟΛΙΤΕΙΕΣ ΑΜΕΡΙΚΗΣ');
        ea_PickListController.getSearchList(testList, 'ΕΛΛ');
    }
}