Refactored Pages API v2 controller
Refactored Pages API v2 controller

refs https://github.com/TryGhost/Team/issues/949
refs https://github.com/TryGhost/Ghost/commit/e64274bb45e948c52d6fbac564f609a24e33ce6e

- This refactor is needed to bring the code in line with the rest of pages API controllers
- Next step will extract shared code patterns into a separate module

e10/Ghost,TryGhost/Ghost,janvt/Ghost,ErisDS/Ghost,janvt/Ghost,e10/Ghost,TryGhost/Ghost,ErisDS/Ghost,ErisDS/Ghost,TryGhost/Ghost