Make removeClippedSubviews toggle-resilient (#56211)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/56211

The `removeClippedSubviews` prop toggle path in `RCTViewComponentView` did not
handle being turned off: children that were clipped (removed from superview)
remained invisible, and `_reactSubviews` became stale.

This diff:
- Adds `_updateRemoveClippedSubviewsState` helper that ensures consistent state
  when toggling. On toggle-off, re-mounts all children from `_reactSubviews` in
  the correct order and clears the tracking array.
- Makes the unmount path resilient by cleaning up `_reactSubviews` even when
  `removeClippedSubviews` is off.
- Splits the unmount assert into two distinct messages: "not mounted" vs
  "mounted inside a different view".
- Adds unit tests covering toggle-off re-mounting, ordering, cleanup, and
  unmount-after-toggle scenarios.

Changelog: [iOS][Fixed] Fixes crash when changing the value of `removeClippedSubviews`

Reviewed By: sbuggay

Differential Revision: D97971845

fbshipit-source-id: c5d0a99e632a23613cc5e05bcf00c2985c30d5b4