feat: specify language for AudioToText

[lukasdotcom]

Resolves: #264
I tested it with french on english audio and it did use french quotation marks << instead of the english ones ".

[kyteinsky]

🚀

[julien-nc]

Sorry I'm a bit late to the party.

There's something missing. I should have been more explicit in the issue.
It would be nice to let the user choose a language in which they will talk in the audio chat feature. I think another (yeah one more) field in the user settings would be good.
Something like "Audio chat language" with a hint like "If you set this, it can improve the transcription of what you say when using the audio chat".

This field value would be stored as a user config value (in oc_preferences with IConfig) and used by the AudioToAudioChatProvider when calling openAiAPIService->transcribeFile.

[lukasdotcom]

Updated the pr to now be able to set a default in the user settings for the language that is used. Still supports the other way of selecting the language for a specific transcribe audio task.

[julien-nc]

Work perfectly.
Optional tit picking (for later maybe): The default input value for language in AudioToTextProvider could be set to the one chosen in the personal settings of the user. In the end it does not matter so much because default is the selected value and it will result in selecting the correct value when processing the task.

[kyteinsky]

ah, noticed after merging there was a comment. Maybe the adjustment can be included in a new PR if required @lukasdotcom ?