node-integration-tests: port AI and gen_ai suites to span streaming

[andreiborza]

Follow the porting recipe in the parent issue.

These suites assert on deep gen_ai attribute sets on child spans, so the { value, type } attribute shape and the collect-across-envelopes rule matter more here than anywhere else.

Suites

• tracing/openai, tracing/openai/openai-tool-calls, tracing/openai/v6, tracing/openai/v7
• tracing/anthropic
• tracing/google-genai, tracing/google-genai-v2
• tracing/vercelai, tracing/vercelai/v5, tracing/vercelai/v6_v7
• tracing/langchain, tracing/langchain/v1
• tracing/langgraph
• aws-serverless/bedrock

Twins to fold back

• tracing/vercelai/span-streaming-v4 and tracing/vercelai/span-streaming-v6 into the matching vercelai suites
• tracing/mcp-server-streamed has no static original, so just drop the suffix

[linear-code]

JS-3608