Add customizable annotations

[tadashiorigami]

Add bbox styling to annotations, stretch the constant h line if constant_h_labels_loc is negative, making the chart look more like the ASRAE default one

[azogue]

Hi @tadashiorigami 👋, thank you so much for contributing 🥳

It looks very good 👍, but it has some collateral damage that I would like to avoid, as, after this change, by default unless specifically configured:

• all text annotations in the chart have a non-transparent bbox
• and the text color doesn't follow the curve color anymore

(that's why there are so many changes in the SVGs stored in tests/example-charts)

⚠️ In addition, it looks like you had some problems with the character encoding? I see the unicode error generated in the SVG (($�C$)), which come from the temperature units, defined as °C, always using '° DEGREE SIGN Unicode: U+00B0, UTF-8: C2 B0'. That character is different from the usual 'º MASCULINE ORDINAL INDICATOR Unicode: U+00BA, UTF-8: C2 BA' in english ANSI keyboards. Not sure what kind of keyboard or python locale config are you using, but everything should run fine with standard UTF-8. Please, open a separate issue if experiencing a problem with this 👍

I will make changes to revert to the previous behaviour (no bbox and color following curve color), by modifying the new AnnotationStyle model, and also remove the bboxs in default_chart_config.json 👍

Then I'll increase the version, update the changelog, and publish a new release 🚀

[azogue]

BTW @tadashiorigami , about

stretch the constant h line if constant_h_labels_loc is negative

do you have any example of this scenario?, so we can add it to the tests suite Already done, got the notebook addition 👍

[tadashiorigami]

Thanks a lot for the merge! That was really quick! As I made a bunch of changes at once, I thought it would take longer for it to be merged. I'm using a Brazilian ABNT keyboard, for some reason I got into some issues when reading/writing without specifying the UTF-8. I'll check it in a separate fork.