fix(datepicker): fix header title templating

Author: didimmova

projects/igniteui-angular/src/lib/date-picker/date-picker.component.ts

@@ -36,7 +36,7 @@ import {
     Validator
 } from '@angular/forms';
 import {
-    IgxCalendarComponent, IgxCalendarHeaderTemplateDirective, IgxCalendarSubheaderTemplateDirective,
+    IgxCalendarComponent, IgxCalendarHeaderTemplateDirective, IgxCalendarHeaderTitleTemplateDirective, IgxCalendarSubheaderTemplateDirective,
      IFormattingViews, IFormattingOptions
 } from '../calendar/public_api';
 import { isDateInRanges } from '../calendar/common/helpers';
@@ -411,6 +411,9 @@ export class IgxDatePickerComponent extends PickerBaseDirective implements Contr
     @ContentChild(IgxLabelDirective)
     public label: IgxLabelDirective;
 
+    @ContentChild(IgxCalendarHeaderTitleTemplateDirective)
+    private headerTitleTemplate: IgxCalendarHeaderTitleTemplateDirective;
+
     @ContentChild(IgxCalendarHeaderTemplateDirective)
     private headerTemplate: IgxCalendarHeaderTemplateDirective;
 
@@ -972,6 +975,7 @@ export class IgxDatePickerComponent extends PickerBaseDirective implements Contr
         this._calendar.locale = this.locale;
         this._calendar.weekStart = this.weekStart;
         this._calendar.specialDates = this.specialDates;
+        this._calendar.headerTitleTemplate = this.headerTitleTemplate;
         this._calendar.headerTemplate = this.headerTemplate;
         this._calendar.subheaderTemplate = this.subheaderTemplate;
         this._calendar.headerOrientation = this.headerOrientation;