fix: SurrealDB vectorestore integration

[martinschaer]

Updated the SurrealDB vectorestore integration.

• integration tests: make integration_tests TEST_FILE=tests/integration_tests/vectorstores/test_surrealdb.py
• other tests: jupyter notebook going to langchain's docs docs: Update surrealdb vectorestore documentation langchain#31199
• format
• lint

[ccurme]

Hello, thanks for this. This adds a net-new integration into langchain-community. We are recommending that new contributions be implemented via separate packages. Would you be interested in publishing an OSS integration package (e.g., langchain-surrealdb)? We've written a walkthrough on this process here:

https://python.langchain.com/docs/contributing/how_to/integrations/

We are encouraging contributors of LangChain integrations to go this route. This way we don't have to be in the loop for reviews, you're able to properly integration test the vector store, and you have control over versioning.

Docs would continue to be maintained in the langchain repo and we would highlight this as a dedicated integration package.

Let me know what you think!