Resolve "Support Required Args"

General MR

Summary

Support a standardized way to get args and specifically support required args.

This doesn't finish all of the work, see this for details.

Relevant logs/screenshots

n/a

Linked Issue

#111 (closed)

Upgrade Notices

Unlikely to affect many people - This unifies how arguments are passed, so if you were reliant on a workflow that did something weird like used an env var that would now override an arg but didn't before because you used a config file to pass it that might break.