Rough cut of repository cluster status panel

Summary:
Ref T4292. This adds some very basic cluster/device data to the new management view. Nothing interesting yet.

Also deal with disabled bindings a little more cleanly.

Test Plan: {F1214619}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T4292

Differential Revision: https://secure.phabricator.com/D15685