[Store] Change StoreInterface to Iterator

[lochmueller]

Hey everyone,

I suggest changing the StoreInterface of the Stores from in the query method from array to iterable.
Stores that are NOT based on a single HTTP request would benefit from the iterator running more memory-efficiently (also the creating of the VectorDocument could be more efficiently if we yield this one-by-one) , since the entire result wouldn't need to be collected in an array.

Depending on the use case, iterator_to_array could still be used (if necessary).

Should I create a PR?

Regards,
Tim

[lyrixx]

Good idea 👍🏼