Add UsingClosestAnchor to ISkinnableDrawable

Also implement it as an auto property in its inheritors.
The auto properties default to true.

osu.Game/Screens/Play/HUD/DefaultAccuracyCounter.cs

@@ -12,6 +12,8 @@ namespace osu.Game.Screens.Play.HUD
         [Resolved(canBeNull: true)]
         private HUDOverlay hud { get; set; }
 
+        public bool UsingClosestAnchor { get; set; } = true;
+
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {