Feels like it's easier to understand this way. The difference of the
maximum scoring values for the entire beatmap and the max values for the
part of the beatmap that has already been played represents the act of
filling the rest of the unjudged objects with maximum results.
Closes#21920.
Weirdly enough this was semeingly fixed once before in ancient times in
3891f467a3, but then unfixed again in
566e09083f. The second change is no longer
needed since the toolbar became opaque in #9447.