[Add] openai compatible code for tts.

[Hardik94]

Issue 26

Custom TTS Provider Shabdabhav -- OpenAI Compatible
Added 2 models for TTS

1. parler-TTS
2. piper-TTS

Esperanto can call self hosted OpenAI-Compatible API server for TTS model and generate the audio based on the requirements.
Other TTS and STT models will be added later on.
New Provider is OpenAI Compatible. so, any TTS provider can easily integrate without code changes

Authentication
Optimization for cache
multi model loading
multi voice audio generation

[Hardik94]

@lfnovo please check the code once.

OPENAI_COMPATIBLE_BASE_URL
OPENAI_COMPATIBLE_API_KEY
Environment Variable is configured in docker.env file . but library is not loading that variable automatically. if someone define manually then it works.
can you please try it on your end ?

[lfnovo]

Will do and let you know

[lfnovo]

I’ve done this on a new branch with the proper code structure to maintain compatibility