HandsSystem Refactor (#38438)

* checkpoint

* pt 2

* pt... i forgot

* pt 4

* patch

* More test fixes

* optimization!!!

* the REAL hand system

* fix RetractableItemActionSystem.cs oversight

* the review

* test

* remove test usage of body prototype

* Update Content.IntegrationTests/Tests/Interaction/InteractionTest.cs

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

* hellcode

* hellcode 2

* Minor cleanup

* test

* Chasing the last of the bugs

* changes

---------

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

Content.Shared/Hands/EntitySystems/SharedHandsSystem.Relay.cs

@@ -41,7 +41,7 @@ public abstract partial class SharedHandsSystem
     {
         var ev = new HeldRelayedEvent<T>(args);
 
-        foreach (var held in EnumerateHeld(entity, entity.Comp))
+        foreach (var held in EnumerateHeld(entity.AsNullable()))
         {
             RaiseLocalEvent(held, ref ev);
         }