Update Phortune Merchant UI to bring it in line with Account UI
This is mostly simpler since the permissions have largely been sorted out already and there's less going on here and less weirdness around view/edit policies.
Test Plan: Browsed all Merchant functions as a merchant member and non-member.
Maniphest Tasks: T13366
Differential Revision: https://secure.phabricator.com/D20733