Rename HTTPFutureResponseStatus subclasses

Summary: Ref T5655. Depends on D10008.

Test Plan: arc unit

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T5655

Differential Revision: https://secure.phabricator.com/D10009