htmlformentry: repeated questions are unable to maintain the order of their answers

This is an inherent limitation of the obs data model, but I wanted to raise this here anyway...

Essentially, any time you ask the same question multiple times on a form, the form is unable to re-display the answers to these questions in the same order as they were entered. This is not great for consistency.

However, I think we'd need to have some sort of link between obs and form field in order to properly support this (and we'd have to use form field in htmlformentry).

Alternatively, we could explore ordering answers by obs_id or some other mechanism to try to achieve a reasonable approximation.