Use ApplicationSearch to manage DrydockLeases

Summary:
Ref T2015. Applies ApplicationSearch to DrydockLease.

This makes the left nav in Drydock a little funky. It will probably get worse for a bit before it gets better, since I want to bring everything to ApplicationSearch and then sort out the details.

Test Plan: Queried leases in Drydock.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2015

Differential Revision: https://secure.phabricator.com/D7827