Should we enable Nostr votes to be recorded even if the federation_id is not been observed?

[tacio]

Currently if it's not in the federations table, the vote is ignored.
But if it's on Nostr it's already public, and it would be interesting to know about thriving federations out there even though we don't have the invite.
Maybe there is a good reason for this...

https://github.com/fedimint/fedimint-observer/blob/master/fmo_server/schema/v4.sql#L6