.Net MEVD: Remove I*VectorStoreRecordCollectionFactory #10534

Currently, each connector has an optional I*VectorStoreRecordCollectionFactory on its *VectorStoreOptions, where the user can provide a factory for collections, for customizing how collections get created when IVectorStore.CreateCollection() gets invoked.

Without this API, users can already instantiate implementations IVectorStoreRecordCollection themselves, passing whatever makes sense to the constructor; this means doing provider-specific, but so does I*VectorStoreRecordCollectionFactory.

I'm assuming the intent here is to allow users to still use the IVectorStore as an abstraction, and still control provider-specific details on how collections are configured when that abstraction is used. If that's indeed the idea, then can people do the same by extending the IVectorStore implementation of their provider (e.g. MyModifiedQdrantVectorStore), and override the GetCollection() method to do whatever they want?

(I'm basically looking to distill the public APIs to the necessary minimum, and see whether advanced user needs can be met simply by composing on top rather than introducing more public APIs. westey (@westey-m) this is a bit similar to our discussion on custom mapper, where it should be possible to layer on top rather than introduce a new concept into the provider itself, etc.)

/cc westey (@westey-m)