[loading] Clean way to add/remove full parts in checkpoint names (#45448)
* try
* fix
* oupsi typo
* oupsi typo
* get rid of dataclasses
* try
* oupsi
* revert from before
* fix
* add parenthesis
* fix
* fix
* fixes
* need to revert the order for saving
* comment
* a bit more general
* simplify
* start adding tests
* typo
* fix dot
* fix
* more tests
* add harder tests
* fix
* improve tests
* comment
* doc
* skip in tests
* fix cohere_asr mapping
* add other needed models to mapping
* add text mappings
* add back
* better comment
* simplify
* remove overriden test
* deduplicate doc