Refactor standing to be ECS (#4142)

* Refactor standing to be ECS

E C S B A B Y

* DONE

* FIX IT FIX IT FIX IT

* IsDown event

* Change to methods

* Fixes

* Address some reviews

* Last of the Mohicans

* Final fixes

* Fix tests

Content.Client/MobState/States/NormalMobState.cs

@@ -7,14 +7,5 @@ namespace Content.Client.MobState.States
 {
     public class NormalMobState : SharedNormalMobState
     {
-        public override void EnterState(IEntity entity)
-        {
-            base.EnterState(entity);
-
-            if (entity.TryGetComponent(out AppearanceComponent? appearance))
-            {
-                appearance.SetData(DamageStateVisuals.State, DamageState.Alive);
-            }
-        }
     }
 }