Allow transcription and summary of big nextcloud talk recordings

[andreydruz]

Describe the feature you'd like to request

Open AI have limit of 25MB file upload

https://community.openai.com/t/whisper-api-increase-file-limit-25-mb/566754

Do not upload video webm file.

Encode it as light ogg file and upload a smaller file.

Describe the solution you'd like

#204

Describe alternatives you've considered

#204