Rename classes for consistency

Summary: These classes are named differently from other PhabricatorEdgeType subclasses. Rename them for consistency.

Test Plan: I would expect the linter to complain if I missed anything.

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11112