Support for pagination/offsetting or setting a range on vector retrieval requests

[kpzen]

It would be great if it was possible to customize the queries sent to different vector databases under additional parameters. For example, many of them (Supabase, Weaviate, Vectara, Qdrant and Singlestore) support pagination, offsetting or setting a range on the query results instead of just returning the top-k. ´This could be great for fetching several larger documents in parallel, and running them through prompts to shorten them before merging everything into a single chain, but to do so you'd need to be able to run separate queries that don't just return the top-k results.