Refactor drag and drop to use a shared interface (#2012)

* WIP in progress hours

* Cleanup

* Fix bugle

* Fix nullable error

* Merge fixes

* Merge fixes

* Merge fixes

Content.Shared/GameObjects/ContentNetIDs.cs

@@ -79,6 +79,8 @@
         public const uint BLOCKGAME_ARCADE = 1073;
         public const uint BODY_PART = 1074;
         public const uint CRAYONS = 1075;
+        public const uint PLACEABLE_SURFACE = 1076;
+        public const uint STORABLE = 1077;
 
         // Net IDs for integration tests.
         public const uint PREDICTION_TEST = 10001;