Decal state handling (#12624)

Content.Shared/Decals/DecalChunkUpdateEvent.cs

@@ -1,12 +1,12 @@
-using Robust.Shared.Map;
 using Robust.Shared.Serialization;
+using static Content.Shared.Decals.DecalGridComponent;
 
 namespace Content.Shared.Decals
 {
     [Serializable, NetSerializable]
     public sealed class DecalChunkUpdateEvent : EntityEventArgs
     {
-        public Dictionary<EntityUid, Dictionary<Vector2i, Dictionary<uint, Decal>>> Data = new();
+        public Dictionary<EntityUid, Dictionary<Vector2i, DecalChunk>> Data = new();
         public Dictionary<EntityUid, HashSet<Vector2i>> RemovedChunks = new();
     }
 }