Review & implements changes for moodle 4.0 https://docs.moodle.org/dev/Moodle_4.0_developer_update#The_course_format_system https://github.com/moodle/moodle/blob/efda17d3b025228da28b7d62366eb11a09fd668e/course/format/upgrade.txt https://docs.moodle.org/dev/Course_formats
