Add Whisper language detection

[ae9is]

See #302

Adds support for automatically detecting language to Whisper tasks.

The existing HuggingFace and Whisper implementations in Python were used as reference: Hugging Face Transformers Original Whisper

Also updates the existing Whisper test suites, including adding a string similarity check for actual model output (as opposed to just output length). Please note that the "new" development dependency for these tests, "fastest-levenshtein" is already used by "webpack-cli".