After consenting, first survey question should be presented

[remomueller]

cc @RebeccaRo

I'll have to double check this, but there are a couple of ways this could occur:

• [ ] Existing user logs in, then consents, then is presented first survey question (or "next available" survey question)
• [ ] Existing user consents, then logs in, and then is presented "next available" survey question
• [ ] New user registers, then confirms email, then consents, then is presented first survey question
• [ ] New user consents, then registers, then confirmation email "confirms" the email and forwards to the first available survey question.

[remomueller]

Ideally, the process would always look for "next available survey question", which in most cases with new users will simply be the first survey question on the first survey.