implement Plotly.js’ localization features in Plotly.py

Forum Tread: https://community.plotly.com/t/how-to-get-plotly-to-use-the-set-locale/43499

TLDR: You can't get Plotly graphs to show in any other language than English (e.g. axis labels for a date axis). The only workaround is to convert every label into a string, but then you loose some important features like tickstops.

The solution would be to get Plotly.py to use the set locale (e.g. locale.setlocale(locale.LC_ALL, "") to set it to the locale of the machine it's running on) - which apparently works in Plotly.js, but not Plotly.py.