Add ability to import/export tagging rules

- Add missing translations
- Add some tests
- Add `/api/taggingrule/export` API endpoint
- Add baggy theme
- Add error message when importing tagging rules failed
- Also fix all translations (I think we are good now)

.gitignore

@@ -32,6 +32,7 @@ web/uploads/
 # Build
 /app/build
 /build
+/coverage
 
 # Composer PHAR
 /composer.phar