snapcraft master has many improvements to allows us relying more on appstream and having to duplicate less crap

example here: https://github.com/apachelogger/snap-appstreamtest

notably snapcraft ideally will be able to extract random appdata, the first of the files listed may is used as "master" info from which the snapcraft description and summary are supplied. additional desktop file and icon extraction should work automatically (this is currently still a bit broken as of right now).

check when we can rely on the improvements and then port all snaps.
OR invent a way we can use snapd, and then use the snapcraft edge snap to get easy access to master builds and use that right away.

relevant upstream bugs
https://bugs.launchpad.net/snapcraft/+bug/1814907
https://bugs.launchpad.net/snapcraft/+bug/1814902
https://bugs.launchpad.net/snapcraft/+bug/1814898
https://bugs.launchpad.net/snapcraft/+bug/1805431
https://bugs.launchpad.net/snapcraft/+bug/1778719
https://bugs.launchpad.net/snapcraft/+bug/1778701
https://bugs.launchpad.net/snapcraft/+bug/1778699
https://bugs.launchpad.net/snapcraft/+bug/1778546
https://bugs.launchpad.net/snapcraft/+bug/1778545