* add ChatCompletionStream Usage return
* ChatCompletionStreamResponse will bot return Usage
* remove the Usage field from the response, it would not be there anyway.
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Co-authored-by: lihang <nasa.li@deepres.com>
* Add model check for chat stream
* Sync model checks
* Fix typo
* Fix functino
* refactor: Refactor endpoint and model compatibility check
* apply review suggestions
* minor fix
* invert return boolean flag
* fix test