[Signup/Login Component] Support i18n

[rickmak]

As title, oursky often need chinese and english. Sometime Italiano.

[louischan-oursky]

We have partial support. We do not support attribute such as placeholder. But we do support component that can take string children

[rickmak]

In making a library easy to use, we should provide default translation for both traditional chinese/simplified and english out of the box.

[louischan-oursky]

I am not sure what you exactly mean. Here is my guess

For each user-facing text, we define a translation key, say "SignupWithMobile.Title". The library by default has "en" "zh-Hant" and "zh-Hans" definitions of all such translation keys. The user now has two choices to customize the text.

1. Provide an alternative translation key
2. Provide a custom text that is used as it is

In order to support this, the underlying localization library has to support cascading when resolving message to use. This also requires user to render a locale provider at the very top of their React component hierarchy for this library as well.

In my opinion, this introduces an extra step of setup and does not give so many benefits. In most cases the user want to customize the text. We also need to extend the localization library to support cascading message resolution.