[Enhancement] Support for Function Calling

[yeahjack]

Dear Developers:

First, let me pay tribute to your fantastic work! It has accelerated my workflow several times without writing a lot of code using multiprocessing or aiohttp.

I wonder if this library could add support for the newly established function calling. It seems that openai-manager has not supported it, which could be an excellent convenience for me.

Thank you very much!

[yeahjack]

I found it actually supports function calling, sorry for raising this issue.