Comment 2 for bug 1923057

I've pushed a branch here: https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/khuckins/lp1923057-course-materials-disassociate-rework

1915556 covers the placed on reserve portion of this, as it includes a "create_time" field for the DB object, so this branch is built atop it. The design of the Course Reserves module has Course Materials set to be deleted entirely upon archival of a course/detachment from a course - this patch reworks this, persisting a disassociated item, while providing a new boolean, is_active, which controls whether or not the item is shown to users on the OPAC.

A future card could expand on this, allowing staff to reassociate items, which would require some tweaks to the associateMaterials function in the EG2 Course Service.