Blackify the whole repo

[javiber]

Ran Black on the entire repo and added a GA to enforce it on new PRs.

We probably want to merge existing PRs first

Questions:

• should we enforce isort?
• should we enforce pylint? if we do, we should only enforce it on norfair/ because doing it on demos/ will raise all sorts of dependencies errors. We should also discuss if we only want to check some warnings

Left the code necessary to enforce them on the GA but it's commented out