EDELIVERY-12752 UI enhancement Users are warned before session expire

[PR] Add icons to the action buttons.

smp-angular/src/app/common/dialogs/session-expiration-dialog/session-expiration-dialog.component.html

 <h2 mat-dialog-title>Extend session</h2>
 <mat-dialog-content>Your session is about to expire in <b>{{data.timeLeft}}</b> seconds!<br />Would you like to logout now or extend it for another <b>{{data.timeout}}</b> seconds?</mat-dialog-content>
 <mat-dialog-actions>
-  <button mat-button mat-dialog-close (click)="onLogoutClicked()" tabindex="-1">Logout</button>
-  <button mat-button mat-dialog-close (click)="onExtendSessionClicked()">Extend</button>
+  <button mat-raised-button mat-dialog-close (click)="onLogoutClicked()" tabindex="-1">
+    <mat-icon>power_settings_new</mat-icon>
+    <mat-label>Logout</mat-label>
+  </button>
+  <button mat-raised-button mat-dialog-close color="primary" (click)="onExtendSessionClicked()">
+    <mat-icon>autorenew</mat-icon>
+    <mat-label>Extend</mat-label>
+  </button>
 </mat-dialog-actions>