Get rid of the OverlayEffectsComponent stuff (#3010)

* Get rid of the OverlayEffectsComponent stuff because it just ended up creating workarounds for it's bugs, without removing any functionality

* Flashes and Flashbangs use the same code now (the Flashable path because it's better)

Content.Server/GameObjects/Components/Mobs/State/MobStateManager.cs

@@ -8,15 +8,5 @@ namespace Content.Server.GameObjects.Components.Mobs.State
     [ComponentReference(typeof(IMobStateComponent))]
     public class MobStateComponent : SharedMobStateComponent
     {
-        public override void OnRemove()
-        {
-            // TODO: Might want to add an OnRemove() to IMobState since those are where these components are being used
-            if (Owner.TryGetComponent(out ServerOverlayEffectsComponent overlay))
-            {
-                overlay.ClearOverlays();
-            }
-
-            base.OnRemove();
-        }
     }
 }