QQuickLoader will resize the item when the item is parented to other item

I need to reparent a loaded item to a different parent for undocking it from my main window, and I need to set the parent back when docking it back. However, when the item is undocked (its parent is not the loader any longer), the QQuickLoader will still resizing the item.

Inside `QQuickLoaderPrivate::_q_updateSize`, there is a check `if (!item) return;`, and I think it needs to be changed to `if ((!item) || item->parentItem() != q) return;`.

There is work around solution, e.g., creating shim layer parent of the loader, but it may create unnecessary more complicate logic.