cmake-gui: Restore application icon on macOS
In !5224 (merged) the macOS icon source file was moved to CMakeGUILib, but it
needs to be directly in the main application in order to be attached to
the .app
in the right place.
Backport: release
In !5224 (merged) the macOS icon source file was moved to CMakeGUILib, but it
needs to be directly in the main application in order to be attached to
the .app
in the right place.
Backport: release