✨ Support for Additional Foundation Models (#906)

- Add support for additional foundation models as feature extractors using the TimmBackbone. 
- Added models include: UNI2, Virchow, Virchow2, kaiko and H-optimus-1. 
- Add more information to docstrings.
- Allow foundation models with additional parameters.

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Shan E Ahmed Raza <[email protected]>

Author: 3 people