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/AI/Utility/AiLogic/UtilityAI.cs

@@ -151,12 +151,12 @@ namespace Content.Server.AI.Utility.AiLogic
         private void DeathHandle(HealthChangedEventArgs eventArgs)
         {
             var oldDeadState = _isDead;
-            _isDead = eventArgs.Damageable.CurrentDamageState == DamageState.Dead || eventArgs.Damageable.CurrentDamageState == DamageState.Critical;
+            _isDead = eventArgs.Damageable.CurrentState == DamageState.Dead || eventArgs.Damageable.CurrentState == DamageState.Critical;
 
             if (oldDeadState != _isDead)
             {
                 var entityManager = IoCManager.Resolve<IEntityManager>();
-                
+
                 switch (_isDead)
                 {
                     case true: