Send setup survey responses to the server

The setup survey presentation & submission logic had gotten disconnected. This hooks them up again so that setup survey responses are actually sent to the server.

Incidentally, as part of that:
* Now setting participant IDs
* Discovered that CHECKBOX questions were missing a name value; added that.
Looking at the models, I'd definitely add some validation. Most of the fields here will contain untrusted value (response text, participant id, survey type etc). You'll also want to make sure these responses are properly sanitized / sanitized when you dump them into an html page for viewing.