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/Disease/Events/AttemptSneezeCoughEvent.cs

@@ -0,0 +1,10 @@
+using Robust.Shared.Audio;
+
+namespace Content.Shared.Disease.Events;
+
+/// <summary>
+///     Raised by an entity about to sneeze/cough.
+///     Set Cancelled to true on event handling to suppress the sneeze
+/// </summary>
+[ByRefEvent]
+public record struct AttemptSneezeCoughEvent(EntityUid uid, string SnoughMessage, SoundSpecifier? SnoughSound, bool Cancelled = false);