MDL-39957 course: added PHPUnit test for the new course_content_deleted event
MDL-39957 course: replaced the course_category_deleted legacy event
MDL-39957 course: added PHPUnit test for the new course_category_deleted event
MDL-39957 course: replaced the course_restored legacy event
MDL-39957 course: added PHPUnit test for the new course_restored event