Modernize Owners a bit

Summary: Update Owners per current UI standards, add crumbs at each level, removed AphrontPanels, check spacing.

Test Plan: Tested a list of owner packages, editing a package, creating a package, and various filters.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11961