Dark mode

[RubendeBruin]

Getting somewhere.

[ ] Colors of nodes in tree are set hard-coded (managed/unmanged/visible)
[ ] Theming of button face does not seem to work. Could be a qt issue?
[ ] but probably better to upgrade to Qt6 before trying further.

see https://github.com/Jorgen-VikingGod/Qt-Frameless-Window-DarkStyle

and https://github.com/gmarull/qtmodern

[RubendeBruin]

Dark mode works with qt6 if application style is set to fusion

[RubendeBruin]

Dark mode 3D view can be reached using HDR environment lights and skybox