Drupal8: Implement set UF locale/language (affects mailing tokens)
This is a follow-up to #17 (closed).
How to reproduce:
- Create a bilingual Drupal site, with the locale module, with URL-prefix language detection (example.org/fr/civicrm)
- Enable multi-lingual CiviCRM, with two languages (ex: FR/EN)
- Send a mailing in French, with the unsubscribe URL token
Expected result: the token should link to the page in French.
Related JIRA issue for Drupal7: https://issues.civicrm.org/jira/browse/CRM-16352