Refactor MedalOverlay to be more readable

Shouldn't really have any functionality changes, just fixing some old
code that I can't easily parse these days.

osu.Game/Overlays/MedalOverlay.cs

@@ -35,7 +35,7 @@ public partial class MedalOverlay : OsuFocusedOverlayContainer
         private IAPIProvider api { get; set; } = null!;
 
         private Container<Drawable> medalContainer = null!;
-        private MedalAnimation? lastAnimation;
+        private MedalAnimation? currentMedalDisplay;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -54,11 +54,7 @@ protected override void LoadComplete()
         {
             base.LoadComplete();
 
-            OverlayActivationMode.BindValueChanged(val =>
-            {
-                if (val.NewValue == OverlayActivation.All && (queuedMedals.Any() || medalContainer.Any() || lastAnimation?.IsLoaded == false))
-                    Show();
-            }, true);
+            OverlayActivationMode.BindValueChanged(_ => displayIfReady(), true);
         }
 
         private void handleMedalMessages(SocketMessage obj)
@@ -86,43 +82,69 @@ private void handleMedalMessages(SocketMessage obj)
             queuedMedals.Enqueue(medalAnimation);
             Logger.Log($"Queueing medal unlock for \"{medal.Name}\" ({queuedMedals.Count} to display)");
 
-            if (OverlayActivationMode.Value == OverlayActivation.All)
-                Scheduler.AddOnce(Show);
+            Schedule(displayIfReady);
+        }
+
+        protected override bool OnClick(ClickEvent e)
+        {
+            dismissDisplayedMedal();
+            loadNextMedal();
+            return true;
+        }
+
+        public override bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
+        {
+            if (e.Action == GlobalAction.Back)
+            {
+                dismissDisplayedMedal();
+                loadNextMedal();
+                return true;
+            }
+
+            return base.OnPressed(e);
         }
 
-        protected override void Update()
+        private void dismissDisplayedMedal()
         {
-            base.Update();
+            currentMedalDisplay?.Dismiss();
+            currentMedalDisplay = null;
+        }
 
-            if (medalContainer.Any() || lastAnimation?.IsLoaded == false)
+        private void displayIfReady()
+        {
+            if (OverlayActivationMode.Value != OverlayActivation.All)
                 return;
 
-            if (!queuedMedals.TryDequeue(out lastAnimation))
+            if (currentMedalDisplay != null)
             {
-                Logger.Log("All queued medals have been displayed!");
-                Hide();
+                Show();
                 return;
             }
 
-            Logger.Log($"Preparing to display \"{lastAnimation.Medal.Name}\"");
-            LoadComponentAsync(lastAnimation, medalContainer.Add);
+            if (queuedMedals.Any())
+            {
+                Show();
+                loadNextMedal();
+            }
         }
 
-        protected override bool OnClick(ClickEvent e)
+        private void loadNextMedal()
         {
-            lastAnimation?.Dismiss();
-            return true;
-        }
+            if (currentMedalDisplay != null)
+                return;
 
-        public override bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
-        {
-            if (e.Action == GlobalAction.Back)
+            if (!queuedMedals.TryDequeue(out currentMedalDisplay))
             {
-                lastAnimation?.Dismiss();
-                return true;
+                Logger.Log("All queued medals have been displayed!");
+                Hide();
+                return;
             }
 
-            return base.OnPressed(e);
+            Logger.Log($"Preparing to display \"{currentMedalDisplay.Medal.Name}\"");
+            LoadComponentAsync(currentMedalDisplay, m =>
+            {
+                medalContainer.Add(m);
+            });
         }
 
         protected override void Dispose(bool isDisposing)