fix(transfer): add trackBy to the list and track by the hide property (#7424)

Author: arturovt

components/transfer/transfer-list.component.ts

@@ -34,7 +34,7 @@ import { TransferDirection, TransferItem } from './interface';
     <ng-template #defaultRenderList>
       <ul *ngIf="stat.shownCount > 0" class="ant-transfer-list-content">
         <li
-          *ngFor="let item of validData"
+          *ngFor="let item of validData; trackBy: trackByHide"
           (click)="onItemSelect(item)"
           class="ant-transfer-list-content-item"
           [ngClass]="{ 'ant-transfer-list-content-item-disabled': disabled || item.disabled }"
@@ -164,6 +164,12 @@ export class NzTransferListComponent implements AfterViewInit {
     return this.dataSource.filter(w => !w.hide);
   }
 
+  trackByHide(_index: number, item: TransferItem): boolean | undefined {
+    // The `validData` is a getter which returns new array each time the property is read.
+    // This may lead to unexpected re-renders, tho the array hasn't been updated.
+    return item.hide;
+  }
+
   onItemSelect = (item: TransferItem): void => {
     if (this.disabled || item.disabled) {
       return;