fix(openai): limit stream_options to official API

[JSap0914]

Summary

• only send OpenAI stream_options: { include_usage: true } to the official OpenAI API
• avoid sending the OpenAI-only field to OpenAI-compatible endpoints such as Databricks
• add regression tests for official and compatible API bases

Fixes #12936.

Verification

• npm --prefix packages/openai-adapters test -- --run src/apis/OpenAI.test.ts
• npm --prefix packages/openai-adapters run build

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