Refactor body component to use slots instead of an army of dictionaries (#3749)

* Refactor body component to use slots instead of an army of dictionaries

* Update vox

* Replace static method call with extension

* Add setpart method, replace dispose with shutdown

* Fix tests, fix not listening to slot events when setting a part

Content.Shared/GameObjects/Components/Body/Part/SharedBodyPartComponent.cs

@@ -57,6 +57,9 @@ namespace Content.Shared.GameObjects.Components.Body.Part
             }
         }
 
+        [ViewVariables]
+        public string DisplayName => Name;
+
         [ViewVariables]
         [DataField("partType")]
         public BodyPartType PartType { get; private set; } = BodyPartType.Other;