From a user's perspective, changing a sort / order mode shouldn't filter
away results, but we were doing this.
In terms of UX expectations, in stable this kind of scenario would
results in a group being added to the end of son select with "Not
ranked" or "Unknown". I think we should aim to match this eventually.
This covers the fail case of removing and adding items (see
https://github.com/ppy/osu/issues/21926) but also covers the proposed
forward implementation, which now considers `DateAdded` and `OnlineID`.