Made a start on scenarios for managings attachments

Note that we are putting these in a sub-folder. Will probably need to
update the cucmber config/jenkins scripts to cope with this.
Basic controller for attachments
Improve double-click protection behaviour

Whilst we want to disable clicked submit buttons to prevent double
form submission, we still want the input to be sent with the form
payload. To do this, we include a hidden input with the same name and
value as the button. This is necessary because browsers do not
include disabled inputs with the payload.
fixup scenario
Adding attachments using new workflow

This gets the basics working. The existing forms are still present in
the UI for the moment. We'll refactor those in a later commit so just
the attachment information is listed without the form fields. We are
also ignoring the handling of consultation responses for now, we'll
get them working with the new workflow in a later commit.