Better typing for model.config (#39132)
* Apply to all models config annotation
* Update modular to preserve order
* Apply modular
* fix define docstring
* fix dinov2 consistency (docs<->modular)
* fix InstructBlipVideoForConditionalGeneration docs<->modular consistency
* fixup
* remove duplicate code
* Delete config_class attribute from the modeling code
* Add config_class attribute in base model
* Update init sub class
* Deprecated models update
* Update new models
* Fix remote code BC issue
* fixup
* fixing more corner cases
* fix new models
* add test
* modular docs update
* fix comment a bit
* fix for py3.9
