Fix dead mobs sneezing and coughing (#12919)

* Fix dead mobs sneezing and coughing

* SneezeCough update

* Streamlined Event code, moved dead-check

* cleanup

* I can has merge?

* Shared event for SharedMobStateSystem

Content.Shared/MobState/EntitySystems/SharedMobStateSystem.cs

@@ -5,6 +5,7 @@ using Content.Shared.Alert;
 using Content.Shared.Bed.Sleep;
 using Content.Shared.Damage;
 using Content.Shared.Database;
+using Content.Shared.Disease.Events;
 using Content.Shared.DragDrop;
 using Content.Shared.Emoting;
 using Content.Shared.FixedPoint;
@@ -58,6 +59,7 @@ namespace Content.Shared.MobState.EntitySystems
             SubscribeLocalEvent<MobStateComponent, UpdateCanMoveEvent>(OnMoveAttempt);
             SubscribeLocalEvent<MobStateComponent, StandAttemptEvent>(OnStandAttempt);
             SubscribeLocalEvent<MobStateComponent, TryingToSleepEvent>(OnSleepAttempt);
+            SubscribeLocalEvent<MobStateComponent, AttemptSneezeCoughEvent>(OnSneezeAttempt);
             SubscribeLocalEvent<MobStateChangedEvent>(OnStateChanged);
             // Note that there's no check for Down attempts because if a mob's in crit or dead, they can be downed...
         }
@@ -68,6 +70,12 @@ namespace Content.Shared.MobState.EntitySystems
                 args.Cancelled = true;
         }
 
+        private void OnSneezeAttempt(EntityUid uid, MobStateComponent component, ref AttemptSneezeCoughEvent args)
+        {
+            if(IsDead(uid, component))
+                args.Cancelled = true;
+        }
+
         private void OnGettingStripped(EntityUid uid, MobStateComponent component, BeforeGettingStrippedEvent args)
         {
             // Incapacitated or dead targets get stripped two or three times as fast. Makes stripping corpses less tedious.