Override SetLifetimeStart/SetLifetimeEnd separately to track individual assignment. It is necessary to ensure real lifetime is not lost when lifetime is partially updated.
Hidden properties are used when the type is the base class. It caused issues when `DrawableHitObject` logic is factored out to `PoolableDrawableWithLifetime` because it is using the base `LifetimeEntry`, not `HitObjectLifetimeEntry`.
Here we use `IHasColumn` to support rulesets with columns, and so I moved that interface out into `osu.Game` from `osu.Game.Rulesets.Mania`.
We also use the same threshold as the unsnap check to ensure that no problems slip through. Specifically where an object is simultaneously not concurrent and not unsnapped but still on the same tick.
It was added in c9f38f7bb6, which
specified 2021 in another place (and was committed in October of 2020
anyway). Update the year so that it doesn't get culled prematurely.