add link, rename tabs, small refactor

src/app/admin/admin-notify-dashboard/models/admin-notify-message.model.ts

@@ -60,6 +60,18 @@ export class AdminNotifyMessage extends DSpaceObject {
   @autoserialize
   object: string;
 
+  /**
+   * The name of the related item
+   */
+  @autoserialize
+  relatedItem: string;
+
+  /**
+   * The name of the related ldn service
+   */
+  @autoserialize
+  ldnService: string;
+
   /**
    * The context of the message
    */