Add Run utility

[J-Marte]

Hello,

I have wrote some Code for a rough implementation of the run-utility over at my Fork in the feature/run branch. It is a separate Flutter-Application so that it can operate independently. I would like to integrate it into this Project. There are still a lot of things to do before it is stable and release ready (wrap into Gnome Extension, Settings, DBus interface naming, documentation, ...).