Add strong test for configuration attributes
# What does this PR do?

This PR adds tests to make sure every possible common kwargs is properly set in all the configurations. This is done by adding a common test in the config tests that tries to set all common attributes to a value different form the default, as set in the dictionary `config_common_kwargs`.

That dictionary is itself tested against a base `PretrainedConfig` to make sure that if we change the defaults or add new attributes, `config_common_kwargs` is also updated.

This should prevent #13992 from happening again.

Fixes #13992
It has been run on all test model files in the second to last commit (before removing a fake modif introduced to trigger all modeling tests). The only failure there was the SQUAD example, failing on master because of the Datasets release.