Add cancel button to create and edit qualification modals (#36)

Co-authored-by: Phan Huy Tran <p.tran@neusta.de>
Reviewed-on: http://git.simonis.lol/angular/ems-frontend/pulls/36
Co-authored-by: Huy <ptran@noreply@simonis.lol>
Co-committed-by: Huy <ptran@noreply@simonis.lol>

src/app/qualification/edit/edit.component.html

@@ -17,6 +17,7 @@
       </mat-form-field>
 
       <mat-dialog-actions align="end">
+        <button mat-button mat-dialog-close>Cancel</button>
         <button mat-flat-button color="primary" type="submit">Edit</button>
       </mat-dialog-actions>
     </div>