Provide locale support for languages we've seen translations for

Summary:
Ref T5267. This isn't exhaustive but should improve support.

As far as I can tell, none of these languages (except emoji) have complicated plural/gender rules (none of the translators have implemented them, third-party sources seem to confirm this).

Test Plan:

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T5267

Differential Revision: https://secure.phabricator.com/D15979