fix(date-picker): invoke markForCheck on opening and closed

Author: ddaribo

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

@@ -904,6 +904,7 @@ export class IgxDatePickerComponent extends PickerBaseDirective implements Contr
             this._initializeCalendarContainer(e.componentRef.instance);
             this._calendarContainer = e.componentRef.location.nativeElement;
             this._collapsed = false;
+            this.cdr.markForCheck();
         });
 
         this._overlayService.opened.pipe(...this._overlaySubFilter).subscribe(() => {
@@ -936,6 +937,7 @@ export class IgxDatePickerComponent extends PickerBaseDirective implements Contr
             this._overlayId = null;
             this._calendar = null;
             this._calendarContainer = undefined;
+            this.cdr.markForCheck();
         });
     }