Follow on work to #766.

This enabled both formatters and applies their changes to the repo.

Additionally, since `black` does not make changes to comments nor
docstrings, we also enable `docformatter` to reformat docstrings which
better aligns with `pydocstyle` rules as well.
Without this additional change (and some manual fixups), `pycodestyle`
and `pylint` would still complain about line lengths, for instance.

Finally, we make a minor adjustment to the max line length setting it to
99 (which is also accepted and mentioned in pep8) instead of 88 to avoid
some comment (especially linter overrides) wrapping.