Fix Lipsum generators for Differential Revisions and Pastes

Summary:
When generating test data to solve a bug I have encountered, I noticed Lipsum was not working correctly for Differential Revisions and Pastes.

It seemed like they weren't updated after some refactoring. This fixes that by updating them.

Test Plan: Run Lipsum for all objects, and note that it has much less failure.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D19534