Implement Pagination for Content libraries

Jira Issue: SOL-4

Provides pagination for content Libraries in the Studio Editing View.

* Partner information: 3rd party-hosted open edX instance, for an edX solutions client (so will need to get some sort of solution merged in)
* Merge Deadline: Next Week, 11th of December
Looks like `present_bu_disabled` make not very good name. Maybe it should be something like `check_navigation_disabled` or something?