Closes https://github.com/ppy/osu/issues/33748.
I (and tests) can't find any regressions from this. One would hope we
aren't relying on fall-through mouse down anywhere beneath buttons..
This is being run in the flow where we are providing a specific beatmap
for immediately selection. In an edge case scenario, the carousel may be
pending on a filter operation, which would cause the whole `SelectAndRun`
call to fail when it doesn't need to.
This is reproduced by multiple test scenes. One example is
`TestSceneOpenEditorTimestamp.TestErrorNotifications`.
This commit changes BeatmapCarouselFilterGrouping to now use floored star
rating when determining which group a beatmap belongs to,
to be consistent with changes introduced here:
https://github.com/ppy/osu/pull/33679.
The AdvancedStats section of the original song select is also
updated to show the floored star rating (rather than rounded).
The fact that the stuff "just worked" previously due to one load-bearing
detach in a random location is really scary because a lot of this was
just not written the way it is supposed to be.