Add token classification support for Cohere model

[hadikhamoud]

What does this PR do?

This PR adds token classification for Cohere:

• CohereForTokenClassification

Before submitting

• [x] Did you read the contributor guideline, Pull Request section?
• [ ] Was this discussed/approved via a Github issue or the forum? Please add a link to it if that's the case.
• [x] Did you make sure to update the documentation with your changes? Here are the documentation guidelines, and here are tips on formatting docstrings.
• [x] Did you write any new necessary tests?

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag members/contributors who may be interested in your PR.

[hadikhamoud]

@LysandreJik Added '# Copied from' in CohereForTokenClassification and test_Cohere_token_classification_model

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the contributing guidelines are likely to be ignored.