Add tokenizers class mismatch detection between `cls` and checkpoint (#12619)
* Detect mismatch by analyzing config
* Fix comment
* Fix import
* Update src/transformers/tokenization_utils_base.py
Co-authored-by: SaulLu <55560583+SaulLu@users.noreply.github.com>
* Revise based on reviews
* remove kwargs
* Fix exception
* Fix handling exception again
* Disable mismatch test in PreTrainedTokenizerFast
Co-authored-by: SaulLu <55560583+SaulLu@users.noreply.github.com>