Limit shuffling of fieldset children

[jessouyangbraven]

Task: https://app.asana.com/0/1170776727341290/1175471955522877, https://app.asana.com/0/1170776727341290/1175281876558207

Test

• Save and Publish content to local canvasweb
• I had to use a new incognito window every time to test JS changes so the browser wouldn't cache it

Inputs we don't shuffle:

• Custom question with email fields from this task: https://app.asana.com/0/1170776727341290/1175471955522877. This has one checkbox input in the fieldset, but a bunch of other types of inputs, so we don't shuffle.
• Checklist question with "other" option. This has a dont-mix class set on it.
• Rate This Module from this task: https://app.asana.com/0/1170776727341290/1175281876558207. This has no checkbox, no radio inputs, don't shuffle.
• Slider questions: again, no checkbox, no radio inputs, don't shuffle.

Inputs we do want to shuffle:

• Plain old checklist
• Plain old radio

Details

• I didn't use the input[type=radio], input[type=checkbox] selector because the inputs in the fieldset are actually wrapped in <div>s to accommodate things like inline feedback, etc., so we are dependent on these specific classnames being in the HTML

[jessouyangbraven]

I've never written jQuery before. I think this is the correct selector syntax?

[rshipp]

lgtm!