Phame - move over blog create + edit to transactions + editor

Summary: Ref T7626. Modernizes the code a bit here so we can eventually make progress on T7626 and other stuff.

Test Plan: made a blog, edited a blog, made errors - stuff looked good

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7626

Differential Revision: https://secure.phabricator.com/D12849