Merge the PO translations with the new template.
This adds the following changes:
- 8000 strings are still valid as is (80%)
- 2000 strings are marked fuzzy and need reviewing (20%)
- 1000 strings are new and need translation
These are based on the `master` API from mid-2020 so they're somewhat outdated.
Some strings will be marked as fuzzy (needs review) and new strings will be
added in the next commit.