`Intl.RelativeTimeFormat` is not displaying correctly for Crowdin server's special `ach-ug` locale

Observed behavior

After following up on the conversation in Slack, I see that the string that uses the standard Intl.RelativeTimeFormat is not displaying correctly in German:

switch to ‘German’ to see this on the in-context server

Expected behavior

Fully translated string.

User-facing consequences

Inability to understand.

Errors and logs

…

Steps to reproduce

#. Go to in-context server #. Switch language to ‘German’ #. Go to Facility > Data

Context

• Kolibri version: 0.14.0b12
• Operating system: all
• Browser: all

[rtibbles]

@jonboiser I think the best way to do what you describe would be to add special detection logic here: https://github.com/learningequality/kolibri/blob/develop/kolibri/core/assets/src/utils/i18n.js#L183 for the ach-ug language code.

If we detect that, we should then update currentLanguage to localStorage.jipt_language_code_kolibri and update languageDirection accordingly too.

By making that shift, it should register all the ach-ug messages as messages for that language instead, and then Kolibri and vue-intl should work seamlessly under the impression that it’s using that language, but using the in context translation messages.

[jonboiser]

This works, but running things locally, I notice a lot of messages are not localized. But this was before I made any changes!