Show file cacheability in Files application

Summary: Ref T5685. We've added a new `canCDN` flag to control whether or not files can be cached and delivered over a CDN. Show this flag in the UI.

Test Plan: Viewed several files, saw correct/expected UI values.

Reviewers: btrahan, 20after4

Reviewed By: 20after4

Subscribers: epriestley

Maniphest Tasks: T5685

Differential Revision: https://secure.phabricator.com/D10213

src/applications/files/controller/PhabricatorFileInfoController.php

@@ -213,6 +213,9 @@ final class PhabricatorFileInfoController extends PhabricatorFileController {
         pht('%s px', new PhutilNumber($height)));
     }
 
+    $finfo->addProperty(
+      pht('Cacheable'),
+      $file->getCanCDN() ? pht('Yes') : pht('No'));
 
     $storage_properties = new PHUIPropertyListView();
     $box->addPropertyList($storage_properties, pht('Storage'));