Ref T6049, Phurl object view should always display some sort of header.

Summary: Ref T6049, Phurl object view should display Phurl name or Phurl long url as header.

Test Plan:

• Create Phurl with no name. Header should show long url as header.
• Add name to Phurl. Header should be new Phurl name.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin

Maniphest Tasks: T6049

Differential Revision: https://secure.phabricator.com/D14502