Implement core_privacy for report progress

Testing can be completed by running the attached testwithmanager.php script (see --- MDL-61571 --- for the original script location) in the Moodle root folder. Make sure you've purged the cache (php admin/cli/purge_caches.php), before running testwithmanager.php. Check that report_progress is compliant Check that report_progress is a null provider Check that the null reason is valid You should receive a script output like: Testing the compliant plugins:   .....   == report_progress (report_progress\privacy\provider) == Claims not to store any data with reason: 'The Activity completion report only shows data stored in other locations.'