Choose view template during create page process

I added an extra step for choosing the view-template first and get all the correct page-parts immediately, while creating a new page.
It doesn't manipulate data as much as set it up - it could be a candidate for a builder object but I'd say it's perfectly fine to live in the controller.

There's no persistence going on here so I wouldn't say it's the responsibility of the model. It's just for showing on the page.