Give HitRenderer a reference to Ruleset

Used to get correct bindings for a mode (ActionMappingInputManager).

osu.Game/Rulesets/Ruleset.cs

@@ -15,12 +15,19 @@ namespace osu.Game.Rulesets
 {
     public abstract class Ruleset
     {
+        public readonly RulesetInfo RulesetInfo;
+
         public virtual IEnumerable<BeatmapStatistic> GetBeatmapStatistics(WorkingBeatmap beatmap) => new BeatmapStatistic[] { };
 
         public abstract IEnumerable<Mod> GetModsFor(ModType type);
 
         public abstract Mod GetAutoplayMod();
 
+        protected Ruleset(RulesetInfo rulesetInfo)
+        {
+            RulesetInfo = rulesetInfo;
+        }
+
         /// <summary>
         /// Attempt to create a hit renderer for a beatmap
         /// </summary>