3.0 architecture revamp/9456/language model featurizer2 (#9586)

Migrated the `LanguageModelFeaturizer` to GraphComponent interface.
* dapted create function to new signature
* implemented required_packages
* renamed `train` to `process_training_data`
* supported multiple messages in `process`
* moved the language check to a separate function.
* adapted process and process_training_data signature
* remove unnecessary tests.

Co-authored-by: Tobias Wochinger <t.wochinger@rasa.com>