Reorg dirs: move `GUIHelpers.*` to `CommonWidgets` subdirectory
Just a small move: moved GUI/Views/GUIHelpers.*
to GUI/Views/CommonWidgets/
because that's the location of widget code of common interest.
Just a small move: moved GUI/Views/GUIHelpers.*
to GUI/Views/CommonWidgets/
because that's the location of widget code of common interest.