Implement core_privacy for null providing activities

Testing can be completed by running the attached testwithmanager.php script (see MDL-61571 for the original script location) in the Moodle root folder. Check that each of the mods are compliant Check that each of the mods state that they're a null provider Check that the null reason is valid You should receive a script output like: Testing the compliant plugins: == mod_folder (mod_folder\privacy\provider) == Claims not to store any data with reason: 'The mod_folder plugin does not store any personal data.' == mod_label (mod_label\privacy\provider) == Claims not to store any data with reason: 'The mod_label plugin does not store any personal data.' == mod_page (mod_page\privacy\provider) == Claims not to store any data with reason: 'The mod_page plugin does not store any personal data.' == mod_resource (mod_resource\privacy\provider) == Claims not to store any data with reason: 'The mod_resource plugin does not store any personal data.' == mod_url (mod_url\privacy\provider) == Claims not to store any data with reason: 'The mod_url plugin does not store any personal data.'