New DCE applications

Ready to merge
GA
3d ago
+14944-4005

VLC, NorthStar web browser, GTK4 patches to DCE.
Plus X11 and PulseAudio forwarding, so most GUI applications can run with audio too.

Requires DCE patch https://github.com/direct-code-execution/ns-3-dce/pull/150
Requires NorthStar patch https://github.com/nordstjernen-web/northstar-browser/pull/17
Even better with extra streaming patches for NorthStar https://github.com/nordstjernen-web/northstar-browser/pull/18