Add rudimentary support of rewinding failed state to health processor

As indicated in the inline comment this is very best effort, just to
make the HP bar not very obviously stuck in a very obviously incorrect
state after the replay is rewound from a failure. There's likely to be a
bunch of replay accuracy issues related to this, but I'm just making the
minimum effort to get this to work semi-acceptably for now.

Author: bdach

osu.Game/Rulesets/Scoring/HealthProcessor.cs

@@ -59,9 +59,16 @@ protected override void ApplyResultInternal(JudgementResult result)
 
         protected override void RevertResultInternal(JudgementResult result)
         {
-            Health.Value = result.HealthAtJudgement;
+            // TODO: this is rudimentary as to make rewinding failed replays work,
+            // but it also acts up (sometimes rewinding a replay several times around the fail boundary moves the point of fail forward).
+            // needs further investigation.
+            if (result.FailedAtJudgement)
+                HasFailed = false;
 
-            // Todo: Revert HasFailed state with proper player support
+            if (HasFailed)
+                return;
+
+            Health.Value = result.HealthAtJudgement;
         }
 
         /// <summary>