Moderize Mailing Lists

Summary: Attempting to learn how to 'modernize' apps so I can update things. Adds a sidenav, crumbs, and views.

Test Plan: Tested creating lists on web and mobile.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4598