Format and lint with black and isort

[jsvgoncalves]

Description

This PR formats and lints the whole codebase with black and isort. Ideally we should install CI/CD checks as well as a pre-commit hook, but at least for now this adds some consistency to the codebase.

More info on ignoring commits in the blame: https://docs.github.com/en/repositories/working-with-files/using-files/viewing-a-file#ignore-commits-in-the-blame-view

[!CAUTION] Do not change the formatting commit or its id will change and the ignore-revs won't work. Merging or rebasing is ok.

Checklist

• [ ] Keep pull requests small so they can be easily reviewed.
• [ ] Update the documentation, please follow the numpy style guide.
• [ ] Update tests.
• [ ] Categorize the PR by setting a good title and adding one of the labels: bug, feature, ui, change, documentation, breaking, ci as they show up in the changelog.
• [ ] Link this PR to related issues by using closing keywords.
• [ ] Add a milestone to the PR (and related issues, if any) for the intended release.
• [ ] Request a review from another developer.

[mrvisscher]

Hi @jsvgoncalves!

Before I can merge, please fix the breaking import order. Activity Browser won't launch with this PR right now because of ImportError's causes by circular imports.

Thanks!