[Idea] Include Flathub, Snapcraft and appimages in Synaptic

[CHJ85]

Hi there. Synaptic is by far the best package manager.
However. For the past decade, we've seen a huge increase in Snap, Flatpak and AppImages.
Because they're universal, distros will be relying on these more and more than they do APT.
My point is, I think it's time for Synaptic to expand its capabilities and add support for these package formats.
If anything, as optional addons. Because I do get why some people want nothing to do with these new formats.