Fix Hands Crash (#122)

* Fixed sprite issues with construction system (Thanks PJB!).

* Storage and Hands Systems now subscribe to Transform Parent changes, and will keep their containers in sync.

* Add check in Interaction System to prevent processing client-side entities on the server.

Content.Server/Interfaces/GameObjects/Components/Items/IHandsComponent.cs

@@ -24,6 +24,12 @@ namespace Content.Server.Interfaces.GameObjects
         /// <returns>The item in the held, null if no item is held</returns>
         ItemComponent GetHand(string index);
 
+        /// <summary>
+        ///     If any hands are holding this entity, immediately remove the entity without dropping it.
+        /// </summary>
+        /// <param name="entity">Entity to be removed.</param>
+        void RemoveHandEntity(IEntity entity);
+
         /// <summary>
         /// Gets item held by the current active hand
         /// </summary>