[to check] verify that we don't fully trust the type name to identify state events
I can't easily say if it is the case or not in Pattle, so opening an issue so I don't forget.
matrix-spec, someone point out that we should check that event are state event by looking up the
stateKey and not trust the
type by itself.
Someone could forge a normal event with type
m.room.name for example, and we shouldn't trust it if it doesn't have a
stateKey. It can be empty, but it should exist.