Spring-ai Support for embedding search with metadata filter expressions

• Extend the VectorStore with similaritySearch with filters method. It is a default implementation that throws an exception for stores that didn't implement it.
• The filters argument is String and vector store type specific.
• Implement the filters for the PineconeVectorStore using the pinecone metadata filters expressions.
• Implement the filters for the PGVector store using the JsonPath expressions on the metadata jsonb column.
• Milvus Vector Store filter predicates support.

Resolves: #75

Comment From: markpollack

Let's add a portable Query/Criteria based API for common operations similar to what is done in Spring Data MongoDB. The search with a String can be used in the case the Query/Criteria based API is not sufficient for users need and they want to pass in a vendor specific query.

Comment From: tzolov

Agree @markpollack , working on it.

Comment From: tzolov

Resolved with: 3615667f054f9531c63862f37b7313d0204fcbf7