Timing points can't fallback to defaults and must be added at least once.
Will be removed in https://github.com/ppy/osu/pull/6604
Not sure why these aren't being detected on master right now - they should be...
Less static weirdness
Fixes up deserializing.
Enforces at CI.
# Conflicts: # osu.Game.Rulesets.Mania/UI/Column.cs