feat: add HNSW vector index for TiDB vector store

[bowenliang123]

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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 TiDB VDB for embeeding column
Vector Column Index requires the service and replicas of TiFlash
doc: https://docs.pingcap.com/tidb/stable/vector-search-index#create-the-hnsw-vector-index

2. Additional context or comments

No response

3. Can you help us with this feature?

• I am interested in contributing to this feature.