Export partial polls

[asterite]

Export all answers even for users that didn't finish the whole poll

[asterite]

• Review if this is already working

[asterite]

This is already working. The only thing I found is that respondents that didn't reply to any question are missing from the CSV. Should we include them anyway?

/cc @spalladino

[spalladino]

I think it could be useful for tracking purposes to show users that didn't reply to any question, and users that accepted the poll but didn't reply (maybe add an extra column with that info?). I'd consider it low-prio, though.