CLC-2631 Format and cache tweaks for bCourse Course Provisioning

https://jira.ets.berkeley.edu/jira/browse/CLC-2631

Busting the user's cache of bCourses-sites is functionally essential, but it makes for a very slow refresh because My Academics is so bulky. I'll create a follow-up ticket to make the Academics feed more fine-grained with its cache management.