Automatically boot a chopsticks instance on the given network after creating a referendum

[seadanda]

Essentially generalise and codify the following flow: https://hackmd.io/@seadanda/BksjUxC91e

I would expect to be able to write:

opengov-cli submit-referendum \
                --proposal "./upgrade-kusama-1.4.1/kusama-1.4.1.call" \
                --network "kusama" --track "whitelistedcaller" \
                --test testfile.{js,ts}

Where the testfile includes:

• pre-run setup (including the chopsticks config)
• post-run assertions

This would take the output calls from submit-referendum, fork the network, upload the preimages and then inject the output calls in the way specified in the above hackmd to simulate a referendum executing from the specified origin.

There should also be a way to generate some scaffolding for the chopsticks test from the tool, e.g.

opengov-cli scaffold-tests --network polkadot

which would output a testfile.ts configured to fork a network including all system chains, fund an account and inject a fellow who could submit the whitelist calls.

A good MVP or example could be limiting ourselves to an upgrade with some hardcoded assertions, attempting to upload the code after it has been authorised etc