perf(item): reorder is only added to the DOM if needed

I have measured the performance impact of this change, since we use the push change detector strategy, the *ngIf is only evaluated once.

Items wrapped around an element with the ListReorder directive will receive a hidden `<ion-reorder>` in their DOM, but items that are not wrapped (i.e. they CAN NOT be reordered) will not even have the `<ion-reorder>` element in their DOM.

fixes #9065

src/navigation/nav-controller-base.ts

@@ -24,6 +24,7 @@ import { TransitionController } from '../transitions/transition-controller';
  * This class is for internal use only. It is not exported publicly.
  */
 export class NavControllerBase extends Ion implements NavController {
+
   _children: any[] = [];
   _ids: number = -1;
   _init = false;