Exposes IOT emeter information using features, bases on #843 to allow
defining the units.
---------
Co-authored-by: Steven B <51370195+sdb9696@users.noreply.github.com>
Also updates CI pypy versions to be 3.9 and 3.10 which are the currently
[supported
versions](https://www.pypy.org/posts/2024/01/pypy-v7315-release.html).
Otherwise latest cryptography doesn't ship with pypy3.8 wheels and is
unable to build on windows.
Also updates the `codecov-action` to v4 which fixed some intermittent
uploading errors.
