feat: add Fiddle snap package

[VerteDinde]

This PR adds a Fiddle snap distributable and tests out our CI setup for snap development.

The current snap binary can be installed by running sudo snap install --dangerous <binary-name>. If we want to upload the build to the official Snap store, we'll have to create an account and vet the binary there. Minus Snap store submission, this PR should be ready for review.

Improvement list:

• Icon behaves differently than .deb and .rpm. Update this in the Forge docs
• "config.features" doesn't contain some of the common plug options by default (i.e. camera, etc). Add them to the installer
• It looks like the "debug" var also auto-adds the "--destructive-mode" flag on snap - remove that and allow end users to pass in command line flags
• The snap binary is huge (250MB?!). Enable LZO compression by default in the upstream installer, which should knock down that binary size

[codebytere]

Looks generally good to me! A few comments but they're non-blocking.