[Redesign] Workboard headers / icons

Summary: Ref T8099, cleans up spacing, colors. Switched back to dropdown icon.

Test Plan: test headers in workpanels, conpherence

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T8099

Differential Revision: https://secure.phabricator.com/D13080

src/applications/project/controller/PhabricatorProjectBoardViewController.php

@@ -678,7 +678,7 @@ final class PhabricatorProjectBoardViewController
     }
 
     $column_button = id(new PHUIIconView())
-      ->setIconFont('fa-gear')
+      ->setIconFont('fa-caret-down')
       ->setHref('#')
       ->addSigil('boards-dropdown-menu')
       ->setMetadata(