Currently the AppImageLauncherLite AppImage is not intuitive. Double-clicking it achieves nothing.

When the AppImageLauncherLite AppImage is double-clicked, a GUI installer should check whether AppImageLauncherLite is correctly installed in the system and if yes, launch it using systemd; if no, install it and then launch it using systemd. Since we are already bundling Qt this should be low overhead.