[epic] [v13] List of current issues, missing features and possible improvements in the new compiler (and relay)

Here we will keep track of the progress of the release/adoption of the new compiler in OSS.

If there is something that is blocking you from adopting the new compiler (and it is not mentioned in this list) please create a new issue, we will review and add it to the list/or trying help with the fix.

The goal: help prioritizing critical bug-fixes/features for upcoming v13.0.2 release (and beyond).

## Current Reported Issues:

Bugs:

- [ ] https://github.com/facebook/relay/issues/3744
- [x] https://github.com/facebook/relay/issues/3760
- [x] https://github.com/facebook/relay/issues/3737
- [x] https://github.com/facebook/relay/issues/3735
- [x] https://github.com/facebook/relay/issues/3726
- [x] https://github.com/facebook/relay/issues/3703 - should be fixed with `relay-compiler@main`
- [x] https://github.com/facebook/relay/issues/3725 - possible fix is https://github.com/facebook/relay/issues/3739
- [ ] #3801
- [x] #3802

Missing Features:
- [ ] https://github.com/facebook/relay/issues/3748
- [x] https://github.com/facebook/relay/issues/3730
- [ ] https://github.com/facebook/relay/issues/3681
- [x] https://github.com/facebook/relay/pull/3666
- [x] https://github.com/facebook/relay/issues/3738

Possible Improvements:
- [x] https://github.com/facebook/relay/issues/3742
- [ ] https://github.com/facebook/relay/issues/3596
- [x] https://github.com/facebook/relay/issues/3438 - note, we now allow some files (.gitkeep/REAMDE to be in the artifactDirectory)
- [x] https://github.com/facebook/relay/issues/3743
- [x] https://github.com/facebook/relay/issues/3739
- [x] Add support for `.gql` file extensions for schema files. See https://github.com/facebook/relay/issues/3772