Remove "arcanist project" controllers
Summary: Ref T7603. Ref T7604. There is no need for these controllers anymore as the "Arcanist Project" data is not used anywhere. Depends on D12894 and D12898.
Test Plan: Went to /repository/project/edit/2/ and got a 404.
Reviewers: Blessed Reviewers, epriestley
Reviewed By: Blessed Reviewers, epriestley
Subscribers: Korvin, epriestley
Differential Revision: https://secure.phabricator.com/D12897