message: Remove unnecessary button ids
diff: </button>
  </mat-menu>
  - <a mat-button id="login" *ngIf="!isLoggedIn()" routerLink="/login" fxShow fxHide.lt-md>
  + <a mat-button *ngIf="!isLoggedIn()" routerLink="/login" fxShow fxHide.lt-md>
  <i class="fas fa-sign-in-alt fa-lg"></i>
  {{"TITLE_LOGIN" | translate }}
  </a>
  - <a mat-button id="logout" *ngIf="isLoggedIn()" (click)="logout()" fxShow fxHide.lt-md>
  + <a mat-button *ngIf="isLoggedIn()" (click)="logout()" fxShow fxHide.lt-md>
  <i class="fas fa-sign-out-alt fa-lg"></i>
  {{"TITLE_LOGOUT" | translate }}
  </a>
  </mat-toolbar-row>
  <mat-toolbar-row fxLayout="row" fxHide fxShow.lt-lg>
  - <a mat-button id="login" *ngIf="!isLoggedIn()" routerLink="/login" fxHide fxShow.lt-md>
  + <a mat-button *ngIf="!isLoggedIn()" routerLink="/login" fxHide fxShow.lt-md>
  <i class="fas fa-sign-in-alt fa-lg"></i>
  {{"TITLE_LOGIN" | translate }}
  </a>
  - <a mat-button id="logout" *ngIf="isLoggedIn()" (click)="logout()" fxHide fxShow.lt-md>
  + <a mat-button *ngIf="isLoggedIn()" (click)="logout()" fxHide fxShow.lt-md>
  <i class="fas fa-sign-out-alt fa-lg"></i>
  {{"TITLE_LOGOUT" | translate }}
  </a>
  