CLC-2802 bCourses course provisioning by CCN

https://jira.media.berkeley.edu/jira/browse/CLC-2802

One known missing piece of functionality: when fetching a candidate course list by CCNs, all the section checkboxes should be selected by default. We can handle that with a followup PR later.

Admin-view formatting is purely functional at the moment -- no extra thought put into the CSS at all.

This adds yet more bulk to an already unwieldy blurt of code. CLC-2825 describes a clean-up task.