Add icon, color and profile image to project.query

Summary:
 - The icon CSS tag is transformed through the new function
   PhabricatorProjectIcon::getAPIName($key), which returns
   a name without fa-.

 - Color is a trivial lookup
 - Profile image returns the PHID or null if not available

Test Plan:
 - Create two projects, with different icon and color,
   one with and one without profile image.
 - Request information on both using project.query
Then:
 [ ] Confirm icon and colors are correct for both projects
 [ ] Confirm image PHID is correct
 [ ] Confirm image PHID is null for the project without image

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: yuvipanda, Korvin, legoktm, epriestley

Maniphest Tasks: T6501

Differential Revision: https://secure.phabricator.com/D10823