chore(*): Prevent focus on click of expanded in header/body.

Author: MKirova

projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.html

@@ -12,7 +12,7 @@
             <span *ngIf="hasMovableColumns && draggedColumn && pinnedColumns.length > 0"
                 [igxColumnMovingDrop]="headerContainer" [attr.droppable]="true" id="left"
                 class="igx-grid__scroll-on-drag-pinned" [style.left.px]="pinnedWidth"></span>
-            <div #headerHierarchyExpander (click)="toggleAll()" [hidden]='!hasExpandableChildren || !hasVisibleColumns' [ngClass]="{
+            <div #headerHierarchyExpander (click)="toggleAll()" (mousedown)='$event.preventDefault()' [hidden]='!hasExpandableChildren || !hasVisibleColumns' [ngClass]="{
                 'igx-grid__hierarchical-expander igx-grid__hierarchical-expander--header': hasExpandableChildren,
                 'igx-grid__hierarchical-expander--push': filteringService.isFilterRowVisible,
                 'igx-grid__hierarchical-expander--no-border': isRowSelectable || rowDraggable

projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-row.component.html

@@ -1,4 +1,4 @@
-<div (click)="expanderClick($event)" [ngClass]="expanderClassResolved" *ngIf="hasChildren" #expander>
+<div (click)="expanderClick($event)" (mousedown)='$event.preventDefault()' [ngClass]="expanderClassResolved" *ngIf="hasChildren" #expander>
         <ng-container *ngTemplateOutlet="iconTemplate; context: { $implicit: this }">
         </ng-container>
 </div>