Support for partitions

[chris-aeviator]

According to qdrant, the optimal strategy for Multitenancy is partioning.

How many collections should you create? In most cases, you should only use a single collection with payload-based partitioning. This approach is called multitenancy. It is efficient for most of users, but it requires additional configuration. This document will show you how to set it up. https://qdrant.tech/documentation/guides/multiple-partitions/

It would be nice if we could have a way to use the same index / documentstore or multiple documentstores (per user) on haystack.