[Feature] Streaming API for Function Calling

[HaoyuWang4188]

This is still a draft for streaming API. And it should be a follow-up PR and should be merged after #2544

Motivation

Modifications

Checklist

• Format your code according to the Contributor Guide.
• Add unit tests as outlined in the Contributor Guide.
• Update documentation as needed, including docstrings or example tutorials.

[merrymercy]

@HaoyuWang4188 Can you rebase, support the streaming and add test cases?

[HaoyuWang4188]

@HaoyuWang4188 Can you rebase, support the streaming and add test cases?

Sure, notice that #2544 is merged. I will rebase this PR and commit the required changes ASAP.

[Tushar-ml]

There is one more PR going on for this functionality: #2700

[merrymercy]

@HaoyuWang4188 @Tushar-ml @YAMY1234 Can you review each other's code?

[HaoyuWang4188]

There is one more PR going on for this functionality: #2700

Sure, I will review #2700 and discuss with the author in slack.