Core/Players: Implemented secondary stat diminishing

Port From (https://github.com/TrinityCore/TrinityCore/commit/cb47605235a49bb2c6065b2e6de69b657a9c905f)

Source/Game/DataStorage/Structs/A_Records.cs

@@ -21,7 +21,7 @@ using System;
 
 namespace Game.DataStorage
 {
-    public class AchievementRecord
+    public sealed class AchievementRecord
     {
         public string Description;
         public string Title;

Source/Game/DataStorage/Structs/G_Records.cs

@@ -222,6 +222,13 @@ namespace Game.DataStorage
         public SocketColor Type;
     }
 
+    public sealed class GlobalCurveRecord
+    {
+        public uint Id;
+        public uint CurveID;
+        public GlobalCurve Type;
+    }
+
     public sealed class GlyphBindableSpellRecord
     {
         public uint Id;