[localization] Add currency, separators, isMetric and update region

[IjzerenHein]

Why

Adds the region property for Android and 4 new properties: currency, decimalSeparator, groupingSeparator and isMetric.

Replaces and closes #10354

How

• Add region property for Android
• Add currency property for iOS and Android
• Add decimalSeparator property for iOS, Android and web
• Add groupingSeparator property for iOS, Android and web
• Add isMetric property for iOS, Android and web
• Fix region property on web when locale contained variants or both region and script
• Update changelog

Test Plan

• Added tests for all new properties
• All tests succeed
• Debugged iOS and Android to verify results

[github-actions]

Native Component List for this branch is ready

[IjzerenHein]

friendly ping to @bbarthec :)

[IjzerenHein]

I think we should go with Option B (the code in this PR) because it lines up with how most of the world works, aside from iOS, and our intent is to create a universal API instead of exposing native APIs. If we want to expose the iOS-specific locale ID, that should go under a separate property named platformLocale that is documented to return a platform-specific string with no guarantee it with be consistent across platforms.

Sounds good. I've made the suggested changes, thank you for reviewing.
I'm in favour of not adding platformLocale unless there is a good reason why people should need this information. So for now, I'd leave it out.

[chybisov]

@IjzerenHein hi, this probably not the right place to ask, but could you please add is24Hour format property? Thank you!

[IjzerenHein]

@chybisov This PR already been merged. If you want that feature added, please create a PR or request the feature on https://expo.canny.io/