Change all of body system to use entities and components (#2074)

* Early commit

* Early commit 2

* merging master broke my git

* does anyone even read these

* life is fleeting

* it just works

* this time passing integration tests

* Remove hashset yaml serialization for now

* You got a license for those nullables?

* No examine, no context menu, part and mechanism parenting and visibility

* Fix wrong brain sprite state

* Removing layers was a mistake

* just tear body system a new one and see if it still breathes

* Remove redundant code

* Add that comment back

* Separate damage and body, component states, stomach rework

* Add containers for body parts

* Bring layers back pls

* Fix parts magically changing color

* Reimplement sprite layer visibility

* Fix tests

* Add leg test

* Active legs is gone

Crab rave

* Merge fixes, rename DamageState to CurrentState

* Remove IShowContextMenu and ICanExamine

Content.Server/GameObjects/Components/Damage/BreakableComponent.cs

@@ -27,13 +27,10 @@ namespace Content.Server.GameObjects.Components.Damage
         public override string Name => "Breakable";
 
         private ActSystem _actSystem;
-        private DamageState _currentDamageState;
 
         public override List<DamageState> SupportedDamageStates =>
             new List<DamageState> {DamageState.Alive, DamageState.Dead};
 
-        public override DamageState CurrentDamageState => _currentDamageState;
-
         void IExAct.OnExplosion(ExplosionEventArgs eventArgs)
         {
             switch (eventArgs.Severity)
@@ -62,7 +59,7 @@ namespace Content.Server.GameObjects.Components.Damage
         public void FixAllDamage()
         {
             Heal();
-            _currentDamageState = DamageState.Alive;
+            CurrentState = DamageState.Alive;
         }
 
         protected override void DestructionBehavior()