Note that this will break rotation loops until https://github.com/ppy/osu-framework/issues/900 is addressed.
Also makes queueing of expand more correct.
Enforces at CI.
# Conflicts: # osu.Game/Graphics/Containers/SectionsContainer.cs
Aso debounce and don't require hitting enter.
Also rename GetBackground to CreateBackground, since it's returning a new instance.
Will likely need to be bindable when hooked up to settings and actually used.