Put Project "Manage" item back

Summary:
Ref T12174. This isn't really a "newManageItem()" since Projects have a separate manage screen.

That is, I incorrectly changed the "Manage [This Project]" item into a "Edit Menu" item, so some options (like "Archive Project") incorrectly became inaccessible.

Test Plan: Viewed a project, saw the right menu item, clicked it, could archive/etc project. Also edited the menu.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12174

Differential Revision: https://secure.phabricator.com/D17275