Implemented layer element saving

Added a working setting to the brush element

src/Artemis.Storage/Entities/Profile/LayerElementEntity.cs

@@ -4,6 +4,8 @@ namespace Artemis.Storage.Entities.Profile
 {
     public class LayerElementEntity
     {
+        public Guid Id { get; set; }
+
         public Guid PluginGuid { get; set; }
         public string LayerElementType { get; set; }
         public string Configuration { get; set; }