Add: num_additional_image_tokens to models (#35052)
* Add: num_additional_image_tokens to models
* docs: update docstring for num_additional_image_tokens in configuration files
* Add num_additional_image_tokens to LlavaNextVideo model and update feature selection logic
* revert
* Fix: adjust num_image_tokens calculation in LlavaProcessor
* Remove num_additional_image_tokens initialization from configuration files
* Fix test error
* revert
* Fix: adjust num_image_tokens calculation in LlavaNextVideoProcessor
* fix conflict
* Fix: adjust num_image_tokens calculation in VideoLlavaProcessor
* make style
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Co-authored-by: Raushan Turganbay <raushan@huggingface.co>
