fix: enable "save" button for Notes and show validation errors clearly (#3778)

fixes #3756

Author: sadaf895

src/app/core/form-dialog/dialog-buttons/dialog-buttons.component.html

@@ -1,7 +1,6 @@
 <button
   mat-raised-button
   color="accent"
-  [disabled]="!form.formGroup.valid"
   (click)="save()"
   angulartics2On="click"
   [angularticsCategory]="entity?.getType()"