Give "PhabricatorUserEmail" a PHID
Ref T13444. To interact meaningfully with "DestructionEngine", objects need a PHID. The "UserEmail" object currently does not have one (or a real "Query").
Provide basic PHID support so "DestructionEngine" can interact with the object more powerfully.
- Ran migrations, checked data in database, saw sensible PHIDs assigned.
- Added a new email address to my account, saw it get a PHID.
Maniphest Tasks: T13444
Differential Revision: https://secure.phabricator.com/D20913