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
Just to make sure - it's not required to write test descriptions like so. I just mocked the way a lot of other descriptions were written. And the reason why they are written like so is that they were converted from lettuce acceptance tests. So this is "kind of" lettuce acceptance test scenario :)