iOs accessibility items loses focus when adding new items

Prerequisite:

1. VoiceOver is enabled
2. Application has an Accessible item selected
3. VoiceOver frame is shown on the item

Steps to replicate:

1. Add a new accessibility item to view

What happens:

1. VoiceOver frame is lost

Notes:

This happens because the iOs accessibility will always destroy all accessibility items and recreate them. Correct way would be to handle objectCreated and objectDestroyed signals without destroying the accessibility items in iOs.

A partial fix can be found here: https://codereview.qt-project.org/c/qt/qtbase/+/299081