Convert StomachBehavior to a component/system + rejig body namespaces (#5249)

* Convert StomachBehavior to a component/system + rejig body namespaces

* test

* slightly more namespace changes

* remove

* Hello?????

* fuck you github test runner

* reviews

* oobsy!

Content.Shared/Body/Components/SharedBodyScannerComponent.cs

@@ -0,0 +1,28 @@
+using System;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Body.Components
+{
+    public abstract class SharedBodyScannerComponent : Component
+    {
+        public override string Name => "BodyScanner";
+    }
+
+    [Serializable, NetSerializable]
+    public enum BodyScannerUiKey
+    {
+        Key
+    }
+
+    [Serializable, NetSerializable]
+    public class BodyScannerUIState : BoundUserInterfaceState
+    {
+        public readonly EntityUid Uid;
+
+        public BodyScannerUIState(EntityUid uid)
+        {
+            Uid = uid;
+        }
+    }
+}