Make all pages have an associated page class

[octopusinvitro]

Problem

We are still in an intermediate state where we send a page object to the relevant template for some routes but not for others. This causes some warnings when running the tests and is a bit inconsistent.

Proposed Solution

Make a dedicated page class for the templates that contain variables and don't use a page.

Acceptance Criteria

Every template that has variables on it should have an associated page class that contains everything the template needs to be rendered.