support json mode response_format

[ljj038]

https://platform.openai.com/docs/guides/text-generation/json-mode
https://platform.openai.com/docs/api-reference/chat/create#chat-create-response_format

[PrimosK]

PR for this is ready (#402) . Waiting for review & feedback...

[namankhurpia]

Hi @ljj038 and @PrimosK

I m not sure when these PRs will be merged

I can assure you if you guys can contribute at my repo, i can assure you I m updating it everyday

https://github.com/namankhurpia/Easy-open-ai

Thanks
Feel free to raise issues there