enable automatic dark-mode switching on macOS
requested to merge ggadinger/kguiaddons:macos-automatic-dark-mode-switch into work/colorschemewatcher
ported over from kconfigwidgets!155 (closed)
Oddly enough the watcher test returns the previously chosen preference when switching the theme -- probably the small Qt app reacts too fast before macOS can change NSAppearance.currentDrawingAppearance? The same code seems to work fine within KConfigWidgets and Kate