Reformat Python code and add CI check

[jw3]

Running black creates changes in about 40 files, which sort of prevents it from being used.

Goals

1. Avoid wasting developer time formatting code
2. Force developers to commit formatted code
3. Enforce a uniform formatting of code across project

The PR to fix this should look like

1. Run black to format all files and commit
2. Add a CI check to the Python CI stage that will fail if there are any unformatted files in the commit

This doesn't need done until there is a lull in dev, ie. post v1.0, but should be done asap after that.