Comma separate likert and checkboxes

I posted this as a combined patch with the other features I posted because this patch depends on the Likert patch that hasn't been looked at yet.

I fixed an issue with the patch that broke non-likert composite elements and committed it to the new issue fork.

@greg boggs I noticed the default value of the convert_date option was changed in this MR. That's unrelated and should go into a separate issue if that change was intentional. I also reverted the changes related to ✨ Use checkbox label instead of value Needs review .

Automatically closed - issue fixed for 2 weeks with no activity.