More general LLM backend support

[you-n-g]

🌟 Feature Description

Currently, only limited numbers of types of LLM is supported in RD-Agent.

Maybe we can add support https://docs.litellm.ai/docs/ to the backend (even replace current implementation) to support more LLMs.

Motivation

1. Application scenario
2. Related works (Papers, Github repos etc.):
3. Any other relevant and important information:

Alternatives

Additional Notes

[ricor07]

Hello, I'd like to join the project by working on this. With a bit of assistance i think I would be able to complete the enhancement task. Can you assign me the issue? Thank you

[SunsetWolf]

Hi, @ricor07

Great, contributing code is very welcome and we provide a template on which you can base your finished code.

Create a new backend/deprec folder under the rdagent/oai folder.

Store the current configuration and code

Implement litellm docking in rdagent/oai/backend folder.

In backend/base.py there is a dummy class APIBackend, the new code needs to inherit from APIBackend.
Code for implementing litellm docking in backend/litellm.py

The template is in the branch name: litellm_backend.