* Replace global 'sendmailtoteacher' setting (checkbox) by 'notifycoursebased' (checkbox):
default for new instances
* Replace global 'sendmailtomanager' setting (checkbox) by 'notifyglobal' (multi-select):
user based selection (users with 'manageapplications' capability in system context)
* Replace instance notification setting (checkbox) by user based selection (multi-select):
enrolled users with 'manageapplications' capability in course context
* Upgrade process:
* if 'sendmailtoteacher' was true, set 'notifycoursebased' true
* if 'sendmailtomanager' was true, set 'notifyglobal' to
"Everyone who can 'Manage apply enrolment'", "Nobody" otherwise
* if instance based notification setting was set to true,
set new user based setting to "Everyone who can 'Manage apply enrolment'", "Nobody" otherwise