🚨🚨 Refactor Image Processors to support different backends (#43514)

* init refactor

* Fix llava

* changes after review

* update first batch of image processors

* refactor part 2

* improve base image processor class, move backends to separate file

* refactor to have backends in separate files, with backends now inheriting from BaseImageProcessor

* fix docstrings

* update some image processors to new refactored standards

* refactor more image processors

* refactor more image processors

* refactor more fast image processors

* refactor more image processors

* refactor more image processor

* improve compatibility with video processors

* refactor more image processors

* add more image processors, improve compatibility with video processors

* support for modular

* refactor modular ima proc

* refactor more modular image processors

* adjustments before merge

* fimish image processors refactor

* update docs

* add fallback to Pil backend for backward compat

* fix repo

* Fix all processors and image processors tests

* fix modular and style

* fix docs

* fix remote code backward compatibility + super in lists

* Update docs and add new model like cli

* fix processor tests

* relax test tvp (used to be skipped)

* fix 4 channels oneformer

* Changes after review

* Fixes after review

* Fix tests

* Change imports in modeling tests to minimize integration tests changes

* fix wrong import

* fix import and missing doc

* fix typo PI0

* Fix all integration tests

* Fix after review, enforce protected torch/torchvision imports in pil image processors (directly in modular model converter)

* Fix style

* Fix test modeling depth pro

* Fix processing_idefics

* Fixes after merge

* _rescale_and_normalize -> rescale_and_normalize

* fix-repo