Make Guide list items use similar CSS as Config items

Summary:
Make entire item clickable instead of only the title (which is a link which is not visually obvious); change background color when hovering.

Closes T16345

Test Plan:
* Install http://phorge.localhost/applications/view/PhabricatorGuideApplication/
* Go to http://phorge.localhost/guides/install/
* Hover over things, click them

Reviewers: O1 Blessed Committers, mainframe98

Reviewed By: O1 Blessed Committers, mainframe98

Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T16345

Differential Revision: https://we.phorge.it/D26502

src/applications/guides/view/PhabricatorGuideListView.php

···
         ->setHeader($item->getTitle())
         ->setHref($item->getHref())
         ->setImageIcon($icon)
+        ->setClickable(true)
         ->addAttribute($item->getDescription());
 
       $skip_href = $item->getSkipHref();