Modernize Repositories a bit

Summary: Switch to modern components, crumbs, pht, object boxes.

Test Plan:
Test browsing a list, click edit, click new repository, click delete, verify all work as expected.

{F330864}

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7427

Differential Revision: https://secure.phabricator.com/D11984