When teacher re-arranges modules and/or sections on the page no event is triggered.

Discovered while testing MDL-44627.
Also 'indent' does not trigger any event (but maybe it should not).

During development please note that:
1. JS (AJAX) and non-JS code is different - see course/mod.php and course/rest.php
2. If module is moved to another section and it's visibility is changed, make sure that course_module_updated event is triggered.
3. Not sure what to do if module is moved to the new position inside the section. Because of our DB design the record in course_modules table is not changed but the course_section one is, but from user/admin point of view this is an update action on module and not section