Add some new (empty) locale translation entries

- fr
- it
- ja
- pl
- ru
- zh

Also fixes the `invoke translate` command (maybe it was changed with the recent update to Django 3.2?)

The CI pipeline now runs the translation and static collection steps, to check those for errors.

.github/workflows/coverage.yaml

@@ -42,6 +42,9 @@ jobs:
           rm test_db.sqlite
           invoke migrate
           invoke import-records -f data.json
+      - name: Test Translations
+          # This will test both the translation and collectstatic functions
+          run: invoke translate
       - name: Check Migration Files
         run: python3 ci/check_migration_files.py
       - name: Upload Coverage Report