Show all photos in a Pholio mock and allow switching between them

Summary: Mock page now shows all images. Switching between images is done by clicking thumbnails.

Test Plan: Verified that all images are shown. Verified that by clicking thumbnail the image clicked will show.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin, AnhNhan

Maniphest Tasks: T2427

Differential Revision: https://secure.phabricator.com/D4698