feat(Qdrant): allow payload indexing

[lambda-science]

This is still a draft:

• I need to modify tests => Index two documents with two differents payload value. Check that user 1 can't access user 2 doc?
• I need to remove the change to opensearch that I pushed too, woopsie

Related doc:

• Payload Index https://qdrant.tech/documentation/concepts/indexing/#payload-index
• Multi Tenancy https://qdrant.tech/documentation/guides/multiple-partitions/

This MR aims to allow Qdrant user to create index on payload (metadata in Haystack naming) field.
This allow to filter way more efficiently vectors when searching.
And also it allows to restricti users to their own vectors only.

I'm open to comments, I'm not sure running it at each start-up of the collection is a good way to do it.
But From Qdrant discord:

andrey.vasnetsov —
overall, we recommed creating payload index before you upload data.
AFAIK, if you try to create same index twice, it won't trigger indexing

https://discord.com/channels/907569970500743200/1214958671742902272/1214958671742902272 (if you are on their discord)

[lambda-science]

Woops, I pushed also my modification to Opensearch... heh, how to revert this