Inlining review and fact check activity fields

as part of [a larger change](https://github.com/alphagov/publisher/pull/251) we inlined all activity fields with the edition form, so that activities and edition changes get submitted in one go. we missed inlining review and fact check activities. so this covers up for that.

also removed an unnecessary template `programmes/_review.html.erb`, and fixed integrations tests failing due to poltergeist getting confused with overlapping elements.
[styleguide](https://github.com/alphagov/styleguides/blob/master/ruby.md#syntax) says booleans shouldn't be initialised with `||=`. How about `render_activity_forms = false unless defined?(:render_activity_forms)` instead?