Make PhabricatorActionListView logged-out user savvy

Summary:
Fixes T2691. Now, all PhabricatorActionListViews in the codebase setObjectHref to $request->getRequestURI. This value is passed over to PhabricatorActionItems right before they are rendered. If a PhabricatorActionItem is a workflow and there is no user OR the user is logged out, we used this objectURI to construct a log in URI.

Potentially added some undesirable behavior to aggressively setUser (and later setObjectURI) from within the List on Actions... This should be okay-ish unless there was a vision of actions having different user objects associated with them. I think this is a safe assumption.

Test Plan: played around with a mock all logged out (Ref T2652) and it worked!

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2691

Differential Revision: https://secure.phabricator.com/D6416