This can be used to hint how the sensor value should be rounded when
displaying it to users.
The values are adapted from the values used by homeassistant.
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.
