Provide Snap package

[dex4er]

We could add Ubuntu Snap packages and distribute them in https://snapcraft.io/

Our electron-builder unfortunately does not support base option so it builds by default for core18 base.

However we can build new Snap package based on existing DEB package (see https://www.electronjs.org/docs/latest/tutorial/snapcraft#using-an-existing-debian-package) then handling Snaps would be separate job in GHA.

We can build and publish separate packages for main repo and nightly.

[dex4er]

Snap must be built outside electron-builder as the used version uses deprecated base18. Also we need additional tweaking for the manifest. Our snapcraft.yaml is mostly created from the Snap package for VScode, including the electron-launch wrapper.

Because Lens uses $HOME/.kube and $HOME/.freelens we must to build it in classic mode: strict mode protects the content of the $HOME directory.

[dex4er]

It makes less sens to distribute Snap packages outside https://snapcraft.io/ (similarly to Flatpaks outside https://flathub.org/). In that case, I'm going to remove Snaps from our releases as we need only DEB package.