fix: added possibility of utilising namespaces

[mateuszkuprowski]

Per request enabled the possibility of utilisng namespace in pinecone connector

[rbiseck3]

I thought we already had support for namespaces? What does this PR solve?

[mateuszkuprowski]

I thought we already had support for namespaces? What does this PR solve?

We did have it yes, but we never used it from platform perspective, only relying on default namespace behaviour so I wanted to add a test before we put this up in production as a feature (alongside minor refactors I did). Turns out my test fails, so I wonder about the functionality as a whole, trying to find if I was the problem or our upsert.

[mateuszkuprowski]

Added passing test verifying that namespaces work correctly. Plus minor refactor in the upsert function and modified descriptions.
Not sure why some of the integration tests are failing, but it has nothing to do with my changes.