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.IntegrationTests/Tests/Interaction/InteractionTest.cs

@@ -1,15 +1,12 @@
 #nullable enable
-using System.Linq;
 using System.Numerics;
 using Content.Client.Construction;
 using Content.Client.Examine;
 using Content.Client.Gameplay;
 using Content.IntegrationTests.Pair;
-using Content.Server.Body.Systems;
 using Content.Server.Hands.Systems;
 using Content.Server.Stack;
 using Content.Server.Tools;
-using Content.Shared.Body.Part;
 using Content.Shared.DoAfter;
 using Content.Shared.Hands.Components;
 using Content.Shared.Interaction;
@@ -135,10 +132,13 @@ public abstract partial class InteractionTest
 - type: entity
   id: InteractionTestMob
   components:
-  - type: Body
-    prototype: Aghost
   - type: DoAfter
   - type: Hands
+    hands:
+      hand_right: # only one hand, so that they do not accidentally pick up deconstruction products
+        location: Right
+    sortedHands:
+    - hand_right
   - type: ComplexInteraction
   - type: MindContainer
   - type: Stripping
@@ -230,20 +230,6 @@ public abstract partial class InteractionTest
                 SEntMan.DeleteEntity(old.Value);
         });
 
-        // Ensure that the player only has one hand, so that they do not accidentally pick up deconstruction products
-        await Server.WaitPost(() =>
-        {
-            // I lost an hour of my life trying to track down how the hell interaction tests were breaking
-            // so greatz to this. Just make your own body prototype!
-            var bodySystem = SEntMan.System<BodySystem>();
-            var hands = bodySystem.GetBodyChildrenOfType(SEntMan.GetEntity(Player), BodyPartType.Hand).ToArray();
-
-            for (var i = 1; i < hands.Length; i++)
-            {
-                SEntMan.DeleteEntity(hands[i].Id);
-            }
-        });
-
         // Change UI state to in-game.
         var state = Client.ResolveDependency<IStateManager>();
         await Client.WaitPost(() => state.RequestStateChange<GameplayState>());