Summary:
Pull Request resolved: https://github.com/react/react-native/pull/57997
`scripts/debugger-frontend/sync-and-build` with `--create-diff` only worked under fbsource, making commit creation (in particular the generated changes table) inconvenient outside of Meta.
This diff lifts commit creation functionality to both Git and Mercurial (`sl`), and makes writing a local commit the default behaviour.
**Changes**
- Synced `debugger-frontend` artifacts are now always committed, regardless of version control backend. Internal Mercurial behaviour is forked to a `fbsource-backend.fb.js` script.
- `--create-diff` is narrowed to draft Phabricator diff submission (fbsource only).
- The script now aborts if there are any working copy changes.
Changelog: [Internal]
Reviewed By: vzaidman
Differential Revision: D116031207
fbshipit-source-id: 8ef3ed465b91d8f71ffa44fd1cba16f28860e3a9
