Clean up watchers and members project page

Summary: Various little fixes, mostly moves information from the "Details" section either into the curtain or into the specific watchers or members list based on user viewership. I think this page is both cleaner and more informative.

Test Plan:
Lock, Unlock, Watch, Join, various projects with multiple users.

{F4959101}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D17891