[Re-Opened] Support for PGVector Database in Autogen (#2439)

* PGVector Contrib Initial Commit - KnucklesTeam:autogen:pgvector_contrib fork

* Update website/docs/ecosystem/pgvector.md

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

* Updated qdrant installation instructions.

* Fixed openai version.

* Added dependencies to install for qdrant and pgvector in contrib tests.

* Added dependencies to install for qdrant and pgvector in contrib tests.

* Cleaned up dependencies.

* Removed flaml out of setup.py. Used only for notebook example.

* Added PGVector notebook link

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Co-authored-by: Chi Wang <wang.chi@microsoft.com>