When the server requests a disconnect due to a user connecting
via a second device, the client will now log the user out on the first
device and show a notification informing them of the cause of
disconnection.
There was a lot of weirdness here, such as storing the playing users,
clearing the playing users from test scenes (!!), and storing the users
being wathed.
This was all a thing because the previous implementation overrode the
base method implementations, which is no longer a thing.