Add llama4 (#3145)
* initial changes
* Add support for other vlm
* cleanup comment
* Improve attn_implementation
* Add comments for support of models
* add model
* add model
* fixes and improvements
* update docker
* Add cache position
* Add tests
* remove redundant changes
* remove tr version
* Upgrade doc + fix linting.
* Fixing the CI.
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Co-authored-by: Nicolas Patry <patry.nicolas@protonmail.com>
