Refactor upgrade tests to allow three way upgrades

[gartnera]

We need the ability to easily test upgrading from version A -> B -> C. I have some hacky tools to do it locally but we should refactor how the upgrade tests work to enable this workflow.

Relates to #2134

TODO:

• [x] always run localnet under cosmovisor and zetaclientd-supervisor to enable upgrading any node image
• [ ] push these images to registry
• [ ] pull base image to start upgrade from docker registry rather than building it every time
• [x] move upgrade proposal submitter to sidecar container. or just push down into e2e.
• [x] serve new binaries via docker run --rm -it --net localnet_mynetwork --ip 172.20.0.109 --name newzeta --entrypoint /usr/bin/python zetanode:v16.0.0 -m http.server and deliver via autodownload
• [x] refactor ssh keygen/injection to allow unification of localnet and prod images