Modernize a few dependencies

A few libraries caught our attention.

- Use a better `urlparse`?
  - https://github.com/python-hyper/rfc3986
  - https://github.com/python-hyper/hyperlink
  - https://github.com/tkem/uritools
  - https://github.com/aio-libs/yarl
- The successor to [`appdirs`](https://pypi.org/project/appdirs/) is [`platformdirs`](https://pypi.org/project/platformdirs/).
