Create simple test qt app using nix

[iurimatias]

We need to create a vanilla qt app using nix, to ensure we can do that without the nix paths issues and without having to worry about any other dependency so that when we do add a dependency and there is an issue we know it's due to that dependency and not something wrong with the packaging process per se.

[iurimatias]

https://github.com/logos-co/simple-qt-app