R1:ae1f0e3b1b68

Introduce ReleephProjectQuery

Summary:
Adds a policy-aware query class for selecting Releeph projects. This doesn't really change anything.

- Make `ReleephProject` implment `PhabricatorPolicyInterface`, beginning the long journey to make it policy-aware.
- Implement `ReleephProjectQuery`, for querying projects using cursor-based, policy-aware paging.
- Use it on the list view, so we load only ~100 projects instead of all of them.
- Tweaked some of the URI routing stuff to make it a little more…