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`).
This matches the expectation from stable where the popover also closes when you press enter. The side-effect is that spacebar also causes it to close, but luckily you don't need spacebar in the popover.
Spotted in passing when reviewing https://github.com/ppy/osu/pull/30080.
The popover would very arbitrarily revert to scaling by Y axis if both
checkboxes were checked off.
Not sure how this passed review.