transformers

1e79eade - SPLIT PR: add user defined symbols and control symbols (#31305)

SPLIT PR: add user defined symbols and control symbols (#31305) * PR SPLIT: moving origina changes for adding user defined symbols * adding gemma test and generalizing gemma converter * ruff * update common test * update serialization test * deberta v2 tests updates as rust version adds '.' as a user added token, so a space is not added * removing commented lines * applying feedback - user only added_tokens to add and check piece.type instead of trainer_spec for user_defined_symbols * add comment referencing sentencepiece