MDL-10232 broke MyMoodle course list sort order (with patch)

MDL-10232 change the call to get_my_courses in order to get all the course fields from the db, but it also removed the sort order criteria from the call (setting it to NULL). This makes the courses appear in creation order (i.e., by internal id), instead of their sort order, like it was before.

The attached patches fix the issue for MOODLE_18_STABLE, MOODLE_19_STABLE and HEAD.