fix(query-builder): remove 'where' span from grid AF

Author: teodosiah

projects/igniteui-angular/src/lib/query-builder/query-builder-tree.component.html

@@ -539,7 +539,9 @@
     </ng-template>
 
     <div class="igx-filter-tree__section" *ngIf="rootGroup || (!rootGroup && (selectedEntity || (entities?.length === 1 && !entities[0]?.name)))">
-        <span class="igx-query-builder__label">Where</span>
+        @if(!this.isAdvancedFiltering()) {
+            <span class="igx-query-builder__label">Where</span>
+        }
         <ng-container
             *ngTemplateOutlet="
                 expressionGroupTemplate;