gnome: add video settings

CMakeLists.txt

src/accountview.cpp

src/models/gtkqsortfiltertreemodel.cpp

src/models/gtkqtreemodel.cpp

src/ringmainwindow.cpp

src/videosettingsview.cpp

src/videosettingsview.h

ui/ringmainwindow.ui

ui/ui.gresource.xml

ui/videosettingsview.ui