Simplify keeping the snap package up to date by including the snapcraft.yaml in the repo.

We can then wire up the snapstore to autobuild the package for amd64,i386,arm* etc.

Many thanks to @elopio for the work of getting ipfs into the snap store in the first place, and to @bertrandfalguiere and @mkg20001 for pushing it forwards.

See: https://github.com/ipfs-shipyard/ipfs-snap

 for more info.

Fixes #7250
WIP #3595

License: MIT
Signed-off-by: Oli Evans <oli@tableflip.io>