Comment 12 for bug 1913604

I added a second commit to that branch to address the feedback. Circ and owning libraries no longer change when being attached to a course.

For testers, note that this behavior typically only appeared when both of these are true:
* the course is at a branch-level, rather than system or consortium
* the material is getting a temporary call number when it is attached

Also a note that this branch resolves bug 1972919.