Add AuthorHref to feed story images

Summary: Fixes T9336. Kind of a bit to back up and find the source, but works easily.

Test Plan: View feed, click on my image.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T9336

Differential Revision: https://secure.phabricator.com/D17322