User Locale
setLocaleForLocalization
Asynchronously fetch the current user's locale from Gandalf and set it as the current locale for all intl and I18nProvider instances. If a network error occurs or if the returned locale is not valid, the en-us locale will be used.
NOTE: if the browser locale is override with either the en-xa or xx-ls pseudo-locale, the override value will be used instead of Gandalf's.