OZG-5730 date-editor use better calendar month icon

alfa-client/libs/ui/src/lib/ui/editor/date-editor/date-editor.component.html

@@ -34,7 +34,9 @@
     (dateInput)="inputEvent($event)"
     (blur)="onBlur()"
   />
-  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
+  <mat-datepicker-toggle matSuffix [for]="picker">
+    <mat-icon matDatepickerToggleIcon>calendar_month</mat-icon>
+  </mat-datepicker-toggle>
   <mat-datepicker #picker></mat-datepicker>
 
   <mat-error>