Fix implicit fallthrough in switch statements (#54290)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/54290

A few places where we fall through intentionally are implicit.  We can make those explicit with `NS_FALLTHROUGH`.  Many places, however, are bugs from failing to add a `break` :eek: -- fix those places too.

These are all found via `-Wimplicit-fallthrough`... we will seek to make this an error by default (vs only in `CompilerWarningLevel.MEDIUM` or higher).

## Changelog:
[iOS] [Fixed] - Add missing `break;` to `-[RCTViewManager pointerEvents]`

Reviewed By: philIip

Differential Revision: D85583441

fbshipit-source-id: e8959b27a2e23ccfc6581286257d5d41b18c5630