Sort init import (#10801)
* Initial script
* Add script to properly sort imports in init.
* Add to the CI
* Update utils/custom_init_isort.py
Co-authored-by: Lysandre Debut <lysandre@huggingface.co>
* Separate scripts that change content from quality
* Move class_mapping_update to style_checks
Co-authored-by: Lysandre Debut <lysandre@huggingface.co>
