Treat relocated files as added files in svn worker.

Summary:
Relocated files aren't treated as newly created files by the worker. This
can lead to the worker trying to look up information about deleted files
in the wrong location.

Test Plan: See T4030

Reviewers: #blessed_reviewers, epriestley

Reviewed By: epriestley

CC: epriestley, aran

Maniphest Tasks: T4030

Differential Revision: https://secure.phabricator.com/D7432