R1:10ffa42504db

Separate locales into more usable groups in the translation menu

Summary:
Ref T5267. Ref T4103. Currently, adding new locale support to the upstream fills this menu with confusing options which don't do anything. Separate it into four groups:

- Translations: these have a "reasonable number" of strings and you'll probably see some obvious effect if you switch to the translation.
- Limited Translations: these have very few or no strings, and include locales which we've added but don't ship translations…