Add fabric implementation to find next focusable view (#50196)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/50196

Currently when `removeClippedSubviews` is enabled on Android keyboard navigation breaks and we can never focus the elements that are clipped. iOS has a similar issue but not as drastic, it only happens when elements on the FlatList have a lot of margin between them.

This algorithm aims to find the next focusable view and return it to native so that we can prevent the clipping of the view on the view clipping algorithm and hence fix keyboard navigation. For more information see D71324219

Fabric algorithm to find the next focusable view given:

`parentTag`: Top most relevant parent of the focused view
`focusedTag`: Tag of the currently focused view
`direction`: Direction in which focus is moving

Changelog: [Internal]

Reviewed By: joevilches

Differential Revision: D71558965

fbshipit-source-id: 1a13c82d067834337e7f7936860780f467c9a15d