Fix/improve default selection of checkboxes and radiobuttons in the MarbleLegendBrowser
completed by: Yazeed Zoabi
mentors: Torsten Rahn, Dennis Nienhüser, Utku Aydın, Andrei Dorian Duma
Currently the default selection of checkboxes in MarbleLegendBrowser specified via the dgml file doesn't seem to work properly.
Ideally maybe also saving per theme would get covered.