Add bark
## What does this PR do?

Fixes #

## TODO

- [x] Add autoregressive text model
- [x] Add autoregressive coarse model
- [x] Add non-autoregressive fine model
- [x] Check text weights
- [ ] Check coarse weights
- [ ] Check fine weights
- [ ] Add Bark model / config -> what design for concatenating the three models?
- [ ] Generation code
- [ ] Update with transformers Encodec checkpoint
- [ ] Docs

Superseded by #24086 