feat: Refactor subscription streaming and plumb through anthropic support (#5105)

* Extract/Refactor OpenAI/AzureOpenAI model interfaces

* Add Anthropic client

* Use new payload type

* run anthropic and fix most of the types

* use abc

* add anthropic to type check dependencies

* add anthropic as a container dependency

* fix tool calls for openai

* add back in token usage

* fix type

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Co-authored-by: Alexander Song <axiomofjoy@gmail.com>