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.Shared/GameObjects/Components/Movement/SharedPlayerInputMoverComponent.cs

@@ -270,7 +270,7 @@ namespace Content.Shared.GameObjects.Components.Movement
         bool ICollideSpecial.PreventCollide(IPhysBody collidedWith)
         {
             // Don't collide with other mobs
-            return collidedWith.Entity.HasComponent<ISharedBodyManagerComponent>();
+            return collidedWith.Entity.HasComponent<IBody>();
         }
 
         [Serializable, NetSerializable]