fix(codegen): Adds manual dirty checking (#621)

- Adds `[ManualDirtyChecking]` for anyone that adds it themselves.
- Adds detection of `[Serializable]` and `[ManualDirtyChecking]` at startup to help identify scripts that need migration.

Projects/Server/Serialization/ISerializable.cs

@@ -20,10 +20,6 @@ namespace Server
 {
     public interface ISerializable
     {
-        // Make sure all properties that will be serialized are calling `MarkDirty()` when they get modified.
-        // This should be done manually or via code gen through SerializedField attribute.
-        // This attribute should be virtual for any base serializalbe type (Item, Mobile, etc) that can be opt-in per type.
-        bool UseDirtyChecking { get; }
         long SavePosition { get; protected set; }
         BufferWriter SaveBuffer { get; protected internal set; }
         int TypeRef { get; }
@@ -43,7 +39,7 @@ namespace Server
         public void InitializeSaveBuffer(byte[] buffer)
         {
             SaveBuffer = new BufferWriter(buffer, true);
-            if (UseDirtyChecking)
+            if (World.DirtyTrackingEnabled)
             {
                 SavePosition = SaveBuffer.Position;
             }
@@ -67,7 +63,7 @@ namespace Server
             SaveBuffer.Seek(0, SeekOrigin.Begin);
             Serialize(SaveBuffer);
 
-            if (UseDirtyChecking)
+            if (World.DirtyTrackingEnabled)
             {
                 SavePosition = SaveBuffer.Position;
             }