* Use Intl for names of languages
* Tweak Intl language style from "American English" -> "US English"
* Update tests
* Fix tests
* Consolidate languageHandler-test files
* Improve coverage
* Consistent casing for languages in dropdown
* Update LanguageDropdown.tsx
* Delint & update snapshot
* Fix tests
* Improve coverage
`of` will fallback to the given code with fallback=code (default)
