Have own Flatpak/Snap packages

The task is to have own, fully controlled Flatpak/Snap packages. There's currently 3rd party driven, Flatpak package: https://www.flathub.org/apps/details/com.github.reds.LogisimEvolution driven by @TheEvilSkeleton however at the end of the day we should have full control of our packages as this is the only way to keep it up to date with official releases (up to now we rely on 3rd party to have a time to package new version once it is released).

This ticket is kind of followup to #678