Replace photo uploads with reminder to make appointment

Instead of having people upload photographs and affirm they've done this we now want to ask them to make an appointment with Photography to have a photo taken in-house. ( RT 224010 ).

This removes the personal data form question about uploading photos and replaces the instructions for the photo with a pointer to Photography. The photo upload URL setting is removed as it's no longer needed. The navigation page template is updated to include a reminder to arrange for a photograph to be taken once the registration is complete. The email to Photography is retained, as that's how they will keep track of who needs to be photographed, but the text is updated.

Closes #9 (closed) as we no longer need to implement this.