I actually thought things were bugged with the previous display method,
since the hinting was very similar to the hover colour/state.
I've adjusted this to hopefully give users a better idea of what this is
intending to show them.
Closes https://github.com/ppy/osu/issues/31098.
Low effort fix because it was already half broken. The test was testing
in isolation but in actual editor usage it wasn't working as expected.
This brings it down to be in line with the flowing elements that usually
do their best to not get in the way.
Decided against putting it in the `HUDOverlay` flow for simplicity. It
will work fine until it doesn't.
The intention here is to make things more testable going forward.
Specifically, to remove the "back-door" entrance into `BeatmapCarousel`
where `BeatmapSets` can be set by tests and bypas/block realm retrieval.