feat: Enhance notification template for better UX

Improved notification display to address issue of a blank box when
clicking the icon. Now, a centered icon with No notification is shown
for a clearer user experience. This change enhances UI clarity and
user-friendliness.

Fix: #2005

Implemented the translation functionality

src/app/shared/notifications-tray/notifications-tray.component.html

@@ -8,6 +8,13 @@
 
 <mat-menu class="mifosx-notifications-menu" #notificationsMenu="matMenu" [overlapTrigger]="false">
 
+  <div *ngIf="unreadNotifications.length === 0" fxLayout="column" fxLayoutAlign="center center" style="padding: 16px;">
+    <mat-icon style="font-size: 24px; opacity: 0.8;">
+      <span class="material-icons">notifications</span>
+    </mat-icon>
+    <p>{{ 'labels.text.No notifications' | translate }}</p>
+  </div>
+
   <button mat-menu-item class="unread" *ngFor="let notification of unreadNotifications" [routerLink]="[routeMap[notification.objectType], notification.objectId]">
     {{ notification.content }}*<br> 
     <span class="time">[{{ notification.createdAt }}]</span>