DDGI updates (#514)

DDGI updates:
- allow 0 raycount to keep static DDGI
- DDGI serialization for saving and loading with scene
- grid dimensions configurable
- refactors

Editor/OptionsWindow.cpp

@@ -656,6 +656,7 @@ void OptionsWindow::Update(float dt)
 {
 	cameraWnd.Update();
 	paintToolWnd.Update(dt);
+	rendererWnd.Update();
 }
 
 void OptionsWindow::ResizeLayout()