Modernize Conduit app a bit

Summary: Remove some AphrontPanels, add some phts, fix some table layouts.

Test Plan: Browse many Conduit pages, test a few calls.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7427

Differential Revision: https://secure.phabricator.com/D11957