Add translations for traditional Chinese

[matthew-white]

This PR makes progress on getodk/central#680, adding translations for traditional Chinese. The only thing that should change in this PR is translations, not any logic.

We've modified the structure of the Transifex JSON since the last release (by adding/removing a string). Due to our process, that means that we also need to update translations for other languages. I've done that in a separate commit in this PR.

Before submitting this PR, please make sure you have:

• [x] run npm run test and npm run lint and confirmed all checks still pass OR confirm CircleCI build passes
• [x] verified that any code or assets from external sources are properly credited in comments or that everything is internally sourced

[matthew-white]

@ktuite, I think this PR just needs a very quick check that it only updates translations.