Fix push room names for rooms with only an alias

Noop get_new_messages_for_device if token hasn't changed

Use state handler instead of get_users_in_room/get_joined_hosts

Add new direct message storage functions to slave store

Start adding store-and-forward direct-to-device messaging

Fix room name in email notifs

Avoid pulling the full state of a room out so often.

Fix None check in backfill

Root the 3PE lookup API within /_matrix/app/unstable

Move ThirdPartyEntityKind into api.constants so the expectation becomes that the value is significant