* Relation -> RelationHistory + TODOs

* Fix: lookup connections for blocking 1:1 convs, not convs directly.

Connect convs do not contain the other user, so in order to find the
other user it's not good to go through that.

* fix: unblock filters unneccessarily on convtype

* Make tests more exhaustive.

Co-authored-by: Stefan Matting <stefan@wire.com>