Improve design of PhabricatorObjectListView

Summary: See discussion in T2014. Aligns this element more closely with @chad's frame_v3.psd mock, and implements the icon/label element. Removes "details".

Test Plan: {F27062} {F27063} {F27064} {F27065}

Reviewers: btrahan, chad

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2014

Differential Revision: https://secure.phabricator.com/D4179