LyShine cleanup of TODOs (#6138)

* LyShine cleanup pass for Atom conversion

Signed-off-by: abrmich <abrmich@amazon.com>

* Add GHI numbers to comments

Signed-off-by: abrmich <abrmich@amazon.com>

Code/Editor/EditorViewportWidget.cpp

@@ -665,13 +665,7 @@ void EditorViewportWidget::OnBeginPrepareRender()
     RenderAll();
 
     // Draw 2D helpers.
-#ifdef LYSHINE_ATOM_TODO
-    TransformationMatrices backupSceneMatrices;
-#endif
     m_debugDisplay->DepthTestOff();
-#ifdef LYSHINE_ATOM_TODO
-    m_renderer->Set2DMode(m_rcClient.right(), m_rcClient.bottom(), backupSceneMatrices);
-#endif
     auto prevState = m_debugDisplay->GetState();
     m_debugDisplay->SetState(e_Mode3D | e_AlphaBlended | e_FillModeSolid | e_CullModeBack | e_DepthWriteOn | e_DepthTestOn);