Damage rework (#2525)

* Make damage work through messages and events, make destructible not inherit ruinable or reference damageable

* Copy sound logic to destructible component for now

* Fix typo

* Fix prototype error

* Remove breakable component damageable reference

* Remove breakable construction reference

* Remove ruinable component

* Move thresholds to individual components and away from damageable

* Add threshold property to damageable component code

* Add thresholds to destructible component, add states to damageable, remove damage container, fix up mob states

* Being alive isn't normal

* Fix not reading the id

* Merge fixes

* YAML fixes

* Grammar moment

* Remove unnecessary dependency

* Update thresholds doc

* Change naming of thresholds to states in MobStateComponent

* Being alive is once again normal

* Make DamageState a byte

* Bring out classes structs and enums from DestructibleComponent

* Add test for destructible thresholds

* Merge fixes

* More merge fixes and fix rejuvenate test

* Remove IMobState.IsConscious

* More merge fixes someone please god review this shit already

* Fix rejuvenate test

* Update outdated destructible in YAML

* Fix repeatedly entering the current state

* Fix repeatedly entering the current state, add Threshold.TriggersOnce and expand test

* Update saltern

Content.Shared/GameObjects/Components/Damage/DamageChangedMessage.cs

@@ -0,0 +1,35 @@
+using System.Collections.Generic;
+using Content.Shared.Damage;
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.GameObjects.Components.Damage
+{
+    public class DamageChangedMessage : ComponentMessage
+    {
+        public DamageChangedMessage(IDamageableComponent damageable, IReadOnlyList<DamageChangeData> data)
+        {
+            Damageable = damageable;
+            Data = data;
+        }
+
+        public DamageChangedMessage(IDamageableComponent damageable, DamageType type, int newValue, int delta)
+        {
+            Damageable = damageable;
+
+            var datum = new DamageChangeData(type, newValue, delta);
+            var data = new List<DamageChangeData> {datum};
+
+            Data = data;
+        }
+
+        /// <summary>
+        ///     Reference to the <see cref="IDamageableComponent"/> that invoked the event.
+        /// </summary>
+        public IDamageableComponent Damageable { get; }
+
+        /// <summary>
+        ///     List containing data on each <see cref="DamageType"/> that was changed.
+        /// </summary>
+        public IReadOnlyList<DamageChangeData> Data { get; }
+    }
+}