[Feature][Frontend]: Add support for stream_options in ChatCompletionRequest

[Etelis]

This PR introduces support for the stream_options parameter in the ChatCompletionRequest class, addressing the feature request in issue #4967.

Changes

• Added the StreamOptions class with an optional include_usage attribute.
• Modified the ChatCompletionRequest class to include the stream_options attribute.
• Updated the chat_completion_stream_generator method to handle the stream_options parameter, allowing optional inclusion of usage statistics in streaming responses.

Fix #4967 (#4967)

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[DarkLight1337]

The code looks good at first glance, but to verify this, let's add some unit tests:

• stream=True, stream_options=None: No usage info returned
• stream=True, stream_options={"include_usage": False}: No usage info returned
• stream=True, stream_options={"include_usage": True}: Usage info returned; check its contents
• stream=False, stream_options={"include_usage": None}: Bad request/validation error
• stream=False, stream_options=None: Usage info returned; check its contents Already covered by existing tests

Could you also update the Completions API handler with stream_options support? I think the logic should pretty much be the same.

[Etelis]

The code looks good at first glance, but to verify this, let's add some unit tests:

* `stream=True, stream_options=None`: No usage info returned

* `stream=True, stream_options={"include_usage": False}`: No usage info returned

* `stream=True, stream_options={"include_usage": True}`: Usage info returned; check its contents

* `stream=False, stream_options={"include_usage": None}`: Bad request/validation error

* ~`stream=False, stream_options=None`: Usage info returned; check its contents~ Already covered by existing tests

Could you also update the Completions API handler with stream_options support? I think the logic should pretty much be the same.

I will try to implement the tests today.
Do you mind me splitting the Completions API to another PR? for clarity..

[DarkLight1337]

Do you mind me splitting the Completions API to another PR? for clarity.

Feel free to do so!

[Etelis]

Added the unit tests.
@DarkLight1337

[DarkLight1337]

Added the unit tests. @DarkLight1337

It seems that there is something wrong with the new schema definition, based on the failing tests.

[DarkLight1337]

Looks good now, thanks for the hard work!