fix(langchain): add provider metadata, route tools to metadata, allowlist span fields#593

Abhijeet Prasad (AbhiPrasad) merged 2 commits into

mainbraintrustdata/braintrust-sdk-python:mainfrom

fix/langchain-spec-alignmentbraintrustdata/braintrust-sdk-python:fix/langchain-spec-alignmentCopy head branch name to clipboard