This was causing state pollution in the new selection. I can't see why
this needs to happen when a selection changes to another.
This fixes https://github.com/ppy/osu/issues/30839 and also the same
issue happening for the new combo toggle.
Tests all seem to pass, and I can't immediately find anything broken,
but YMMV.
This was another IRL request from a mapper / team member. The rationale
here is that it can be very annoying to map with break time enabled if
you have a large gap in the beatmap you are trying to fill with
hitobjects, as you are placing objects on top of a very gray area.
More specifically, this fixes placement blueprints not beginning placement when using touch input while the cursor was previously outside compose area, due to the placement blueprint not existing (removed from the scene by `ComposeBlueprintContainer`).