Add ColPali to 🤗 transformers

[tonywu71]

What does this PR do?

Add ColPali support in 🤗 transformers.

Who can review?

@yonigozlan 😉

Additional details

• This PR uses the new Modular 🤗 transformers feature from v4.45.0
• The ColPali is mainly inspired from the repository I'm maintaining with my co-authors. The code is taken from colpali-engine==v0.3.0.

Progress checklist

TODO

• [x] (Optional) Understood the model’s theoretical aspects
• [x] Prepared 🤗 Transformers dev environment
• [x] Set up debugging environment of the original repository
• [x] Created script that successfully runs the forward() pass using the original repository and checkpoint
• [x] Successfully added the model skeleton to 🤗 Transformers
• [x] Successfully converted original checkpoint to 🤗 Transformers checkpoint
• [x] Successfully ran forward() pass in 🤗 Transformers that gives identical output to original checkpoint
• [ ] Finished model tests in 🤗 Transformers
• [x] Successfully added tokenizer in 🤗 Transformers
• [ ] Run end-to-end integration tests
• [ ] Finished docs
• [ ] Uploaded model weights to the Hub
• [ ] Submitted the pull request
• [ ] (Optional) Added a demo notebook