Still need to grab it on the room-level from the room state if possible,
otherwise just rollback to the MXID.
I also need to consider profile pictures and bridging media, and check
if the nick was present XMPP-side first, as that can and will cause
issues, especially around semi-anonymous MUCs.
Still lots of things required(like using the users JIDs whenever
possible, otherwise dropping to occupant ID), images, replies, rich data
with HTML and whatever XMPP has, etc...
