feat: chat api

[jclab-joseph]

OpenAI compatible API Endpoints.

config example:

server:
  api:
    port: 9801
    openai:
      enabled: true
      chat_completions_queue: "example/chat"
      completions_queue: "example/completions"
      embeddings_queue: "example/embeddings"

worker example: https://github.com/jc-lab/distworker/blob/d02779349d87d8f92777b30fa1988fe232cf0a1d/python/examples/modal-worker.py