628-add role of checkbox to panel items and label group

[Amberroseweeks]

This closes issue: https://github.com/orgs/CodeForPhilly/projects/3?pane=issue&itemId=61905665&issue=CodeForPhilly%7Cclean-and-green-philly%7C628

I checked this in Apple VO and it does seem to work. Would love another perspective and look though. I feel like we could use a more dynamic approach to the aria-label, maybe using aria-labeledby and targeting the h2, I struggled to get the correct h2, it would just target the first h2 on the page.