Feat: Create PRs to the sms repo from Sandbox

[murderteeth]

from @flashfish0x

A functionality I always wanted to add was integration with github. For instance on the sandbox page when you get the code snippet, or on the single vault page when you do an adjust ration. We use that code snippet to do a multisig transaction on ethereym or fantom. That is done by pasting that code into a github repository and then opening a pull request at which point a bot takes over to simulate the transaction and push it to the chain. Being able to go straight from seafood to the github pull request without copy and pasting would be great.

requires #71

Here's an example of how to PR the sms repo:
https://github.com/yearn/dashboard_ui/blob/208a9fdf9bb3a48406dbec58646a8a7991069e10/src/components/Vault/Code.js#L147