Add support for setting a labeled list of checkboxes

[mfulton26]

e.g.

<fieldset>
    <legend>Shipping Options</legend>
    <label><input type="checkbox" id="giftWrap">Gift wrapped?</label>
    <label><input type="checkbox" id="warranty">Warranty?</label>
    <label><input type="checkbox" id="returnable" checked>Returnable?</label>
</fieldset>

await automator.set("Shipping Options").to({
  "Gift wrapped?": true,
  "Warranty?": false,
  "Returnable?": true
});