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.
A previous attempt at this was unsuccessful due to a partially
off-screen elements not getting the correct size early enough (see
https://github.com/ppy/osu/issues/14793). This can be accounted for by
setting `AlwaysPresent` when visibility is expected.
This fixes [test failures](https://github.com/ppy/osu/actions/runs/6838444698/job/18595535795)
due to the newly added `Width` / `Height` being persisted with
floating-point errors (by not persisting the values in the first place,
via `AutoSize.Both`).
They were broken because `SerialisedDrawableInfo` is a reference type
and as such equality checks will use reference equality rather than
member equality.