Refactored shape brushes to use the properties system

src/Artemis.Core/Constants.cs

@@ -1,4 +1,5 @@
 using System;
+using Artemis.Core.Plugins.Models;
 
 namespace Artemis.Core
 {
@@ -6,5 +7,6 @@ namespace Artemis.Core
     {
         public static readonly string DataFolder = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData) + "\\Artemis\\";
         public static readonly string ConnectionString = $"FileName={DataFolder}\\database.db;Mode=Exclusive";
+        public static readonly PluginInfo CorePluginInfo = new PluginInfo {Guid = Guid.Parse("ffffffff-ffff-ffff-ffff-ffffffffffff"), Name = "Artemis Core"};
     }
 }