TF port of ESM
Working out the last few issues now! Models <3B parameters have been ported already, larger models will need to wait for #19124. 

This PR also includes fixes for a couple of issues in the original PyTorch ESM.
_The documentation is not available anymore as the PR was closed or merged._<|||||>Pipeline tests are failing because the model has no SEP token and doesn't work with multiple sequences. Working on it!<|||||>There's one final test remaining that's failing because of some arcane issue in the code that generates data batches for the pipeline. I'm trying to figure it out!<|||||>Tests are green, and #19124 has been merged! Going to use it to upload the remaining checkpoints and then merge this.