Support locale config for rx.plotly

[cheronder]

Describe the Features
Add support for configuring Plotly locale in rx.plotly.

• What is the purpose of the feature?
  Allow developers to set chart locale (e.g. zh-CN, de-DE, fr-FR) so that numbers, dates, axis labels, and modebars follow user language and regional formats.

• Show an example / use cases for the new feature.
  Per chart: rx.plotly(data=..., layout=..., locale="zh-CN")
  Global: maybe rx.Config(plotly_locale="zh-CN")

Additional context
reference: https://www.npmjs.com/package/plotly.js-locales