add some mised translations to html files

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

@@ -1,4 +1,4 @@
-<button 
+<button
   mat-icon-button class="ml-1" matTooltip="Notifications"
   [matMenuTriggerFor]="notificationsMenu" (menuClosed)="menuClosed()"
   [matBadge]="unreadNotifications.length" [matBadgeHidden]="!unreadNotifications.length" matBadgeColor="warn"  matBadgeSize="medium"
@@ -10,18 +10,18 @@
 
   <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>
+      <span class="material-icons">{{'labels.menus.Notifications' | translate}}</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> 
+    {{ notification.content }}*<br>
     <span class="time">[{{ notification.createdAt }}]</span>
   </button>
 
   <button mat-menu-item *ngFor="let notification of displayedReadNotifications" [routerLink]="[routeMap[notification.objectType], notification.objectId]">
-    {{ notification.content }}<br> 
+    {{ notification.content }}<br>
     <span class="time">[{{ notification.createdAt }}]</span>
   </button>