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.Client/GameObjects/Components/PlaceableSurfaceComponent.cs

@@ -1,11 +1,41 @@
+#nullable enable
 using Content.Shared.GameObjects.Components;
 using Robust.Shared.GameObjects;
 
 namespace Content.Client.GameObjects.Components
 {
     [RegisterComponent]
+    [ComponentReference(typeof(SharedPlaceableSurfaceComponent))]
     public class PlaceableSurfaceComponent : SharedPlaceableSurfaceComponent
     {
+        private bool _isPlaceable;
 
+        public override bool IsPlaceable
+        {
+            get => _isPlaceable;
+            set
+            {
+                if (_isPlaceable == value)
+                {
+                    return;
+                }
+
+                _isPlaceable = value;
+
+                Dirty();
+            }
+        }
+
+        public override void HandleComponentState(ComponentState? curState, ComponentState? nextState)
+        {
+            base.HandleComponentState(curState, nextState);
+
+            if (!(curState is PlaceableSurfaceComponentState state))
+            {
+                return;
+            }
+
+            _isPlaceable = state.IsPlaceable;
+        }
     }
 }