chore(*): remove required from return fields combo

Author: igdmdimitrov

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

@@ -11,7 +11,7 @@
     class="igx-query-builder__main"
     (scroll)="onExpressionsScrolled()"
 >
-    <ng-container *ngIf="!rootGroup">
+    <ng-container *ngIf="!rootGroup && this.entities.length > 0 && !this.entities[0].name">
         <div class="igx-query-builder__root">
             <div class="igx-query-builder__root-actions">
                 <button type="button"
@@ -455,7 +455,6 @@ <h6 class="igx-filter-empty__title">
                             [overlaySettings]="returnFieldSelectOverlaySettings"
                             searchPlaceholder="{{ this.resourceStrings.igx_query_builder_search }}"
                             [style.display]="isInEditMode() ? 'block' : 'none'"
-                            [required]="true"
                         >
                             <ng-template igxComboHeader>
                                 <div
@@ -522,7 +521,7 @@ <h6 class="igx-filter-empty__title">
         </div>
     </ng-template>
 
-    <ng-container *ngIf="rootGroup">
+    <ng-container *ngIf="rootGroup && this.entities.length > 0 && this.entities[0].name">
         <ng-container
             *ngTemplateOutlet="
                 expressionGroupTemplate;