R1:9f8dde9cf603

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…