Whisper model size selection

[lucksus]

Until here we had the exact whisper model source hard-coded to the medium size model which still runs okish on CPU. But on >=M1 macs we could easily use bigger/better models to have better accuracy.

With these changes, the Whisper model size can be changed in the AI settings.

• Use a good default size during setup for different cases

The base branch was changed.