fix(ui): self managed field paths

[jacobsfletch]

Fixes #12286. Self managed fields, i.e. custom fields that define their own path as a prop, consume their parent's path instead of the path that was given to them.

This was introduced in #11973 where we began passing a new potentiallyStalePath arg to the useField hook that takes the path from context as priority. This change was necessary in order to fix stale paths during row manipulation while the server is processing.

This change, however, made it so that custom fields could no longer control their own path.

The fix is to lift the potentiallyStalePath logic out of Payload's default fields and pass it as a direct prop. This way the path prop is still available for direct use.