Moderation support

[jwr1]

• [x] View magazine moderators: babab48e3f4a6023807a2558098b1315b6f3c828
• [x] Edit magazine details: a43e3b3053bd3065045a7b7eb3d68ff3abf1818c
• [ ] Mod actions (pin, remove, etc.) on content
• [ ] Create magazine
• [ ] View and manage reports