[User Settings] Include Conversations in Course-Level notification preferences

[audra_agnelly]

On the course-level notifications screen users can completely opt-out of notifications from a particular course or customize individual notification types. I learned today that a user who had opted out of notifications for a course was still receiving Inbox message. It seems this selection is not even included in the course notification type list at the course level and is not scoped when they opt out of all notifications for the course. Users can opt out of inbox notifications in their account level settings, if they do not want inbox notifications from specific courses, they should be able to opt out like they can for any other notification type.