[API Compatibility] enhance `paddle.enable_compat` -part (#79391)

* new compat mechnism

* fix

* re-use func, simplify the logic

* fix slogdet been skipped convert

* further simplify the logic

* add metaclass for class Linear; remove the __instancecheck__ and __subclasscheck__ in api_dispatch.py

* implement general metaclass

* use a clearer naming, add test coverage

* root include paddle.compat