MDL-38688 behat: Steps definitions for backup/restore
MDL-38688 behat: Backup tests

Complemented by restore_moodle2_courses.feature
tests.
MDL-38688 behat: Restore Moodle 2 courses tests
MDL-38690 behat: Step definition to import a course
MDL-38690 behat: New test

According to MDLQA-327, a teacher can
import data from another course.