feat(vdb): add HNSW vector index for PG vector store

[huangzhuo1949]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

Add the HNSW vector index in PG VDB for embeeding column
https://github.com/pgvector/pgvector?tab=readme-ov-file#indexing

2. Additional context or comments

No response

3. Can you help us with this feature?

• I am interested in contributing to this feature.

[huangzhuo1949]

#12338