Support audio input and output in `/chat/completions`

[mudler]

Is your feature request related to a problem? Please describe.
It is now possible to pass audio input and receive audio output as well in OpenAI. For more information: https://x.com/OpenAIDevs/status/1846972985170972923

Describe the solution you'd like
LocalAI to support the OpenAI API endpoints

Describe alternatives you've considered

Additional context
https://platform.openai.com/docs/guides/audio

Partly tied to #3602 #3714