Move Drydock object list rendering to SearchEngine
Summary: Ref T4986. Allows the Drydock search engines to render as panels.
Test Plan: Viewed affected interfaces in Drydock. Created panels from each engine.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T4986
Differential Revision: https://secure.phabricator.com/D9103