add Ubuntu Core Desktop support

[peter-kal]

A good opportunity for it to be more wildly tested and used, will be to consider Ubuntu Core Desktop. It's basically the all-snap Ubuntu Core OS for desktop and it will land this October as an extra version of Ubuntu Desktop.
Due to snaps and immutability someone could easily switch between DE with a simple command like:
sudo snap install fynedesktop
The DE can be packaged as a snap, a Desktop Session, and it will also be confined. I figured to suggest this because in a system where you can easily and break free install a DE, revert back to previous editions if something goes wrong, testing or even daily-driving for FyneDesktop should be more viable.
I will leave some helpful links:
More about the Ubuntu Desktop Session concept:
https://discourse.ubuntu.com/t/ubuntu-core-desktop-the-desktop-session/38536

More about Ubuntu Core Desktop:
https://discourse.ubuntu.com/t/ubuntu-core-desktop-deep-dive/37740

An example of how it's currently implemented:
https://forum.snapcraft.io/t/manual-review-of-plasma-desktop-session-snap/40403
PS1: I want to also apologize because as of now I don't have the expertise to assist meaningfully, I will try tho to contribute further.
Edit: core snap technologies are built with go so ig language solidarity

[andydotxyz]

Sorry I missed this. What do we need to do - just support packaging as a Snap?

We don't really do custom platform packaging types at this time, as the packages need champions and maintenance time that we don't currently have.