move task to left tooltip on normal task

src/app/pieces/tasks/task/task.component.html

@@ -6,7 +6,9 @@
     <div class="piece-attach piece-attach-right" [style.background]="task.supplementaryRole ? task.supplementaryRole.color : 'var(--piece-background-color)'"></div>
 
     <div class="piece-menu" [class]="displayMenu">
-        <mat-icon fontIcon="arrow_back_ios" (click)="moveTask('left')" *ngIf="canMoveTo('left')"></mat-icon>
+        <mat-icon fontIcon="arrow_back_ios" (click)="moveTask('left')" *ngIf="canMoveTo('left')"
+        matTooltip="Décaler la tuile vers la gauche."
+        matTooltipPosition="above" [matTooltipDisabled]="!tooltipService.activatedTooltips"></mat-icon>
         <div>
             <mat-icon fontIcon="change_circle" [matMenuTriggerFor]="menuChange"
             matTooltip="Changer le type de cette tuile."