This wasn't a thing yet, so the search experience compared to something
like Element Web was much worse. Now you can scroll back as far as any
other client can!
I had to do a bit of refactoring to stop resetting the model all the
time, and append instead. Otherwise, it was quite straightforward to
implement.
In other messaging applications (e.g. Discord) this is possible through
text modifiers like "from:@user". We don't support that, and I'm not
super keen on implementing yet-another-parsing-thing, so an action in
the user detail dialog should work for now.
Very useful to sift through large rooms but when you only care about a
specific person's messages (maybe your own?)
