community: added FalkorDB vector store support i.e implementation, te…

…st, docs an… (#26245)

**Description:** Added support for FalkorDB Vector Store, including its
implementation, unit tests, documentation, and an example notebook. The
FalkorDB integration allows users to efficiently manage and query
embeddings in a vector database, with relevance scoring and maximal
marginal relevance search. The following components were implemented:

- Core implementation for FalkorDBVector store.
- Unit tests ensuring proper functionality and edge case coverage.
- Example notebook demonstrating an end-to-end setup, search, and
retrieval using FalkorDB.

**Twitter handle:** @tariyekorogha

---------

Co-authored-by: Erick Friis <[email protected]>