Phriction - kill the old PhrictionDocumentEditor

Summary:
Ref T4029. Long live PhrictionTransactionEditor...! this means that all existing functionality runs 100% through the modern transactions + editor framework. this diff does a few things in sum

 - kills the old editor
 - moves conduit-based edits to new editor
 - moves stubbing out documents to new editor
 - deletes moving of wiki docs for projects functionality... (T4021#59511 is a better bigger battle plan here.)

Test Plan: edited a phriction document via conduit and it worked. created a new phriction document /that/was/deep/ and verified ancestral documents were properly stubbed out. changed a project name and noted no wiki page moves.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T4029

Differential Revision: https://secure.phabricator.com/D10792