fix: improve id detection/replacment for Toggler `aria-controls` attribute
fix: improve id detection/replacment for Toggler `aria-controls` attribute

Changes:
* Only add the id if it does not exist in `aria-contolers` with better RegExp detection
* Use ES6 features to simplify code
* Add comments

colin-marshall/foundation-sites,DaSchTour/foundation-sites,zurb/foundation,zurb/foundation-sites,atmmarketing/foundation-sites,zurb/foundation,denisahac/foundation-sites,zurb/foundation-sites,abdullahsalem/foundation-sites,zurb/foundation-sites,zurb/foundation,atmmarketing/foundation-sites,colin-marshall/foundation-sites,abdullahsalem/foundation-sites,DaSchTour/foundation-sites,denisahac/foundation-sites,colin-marshall/foundation-sites,atmmarketing/foundation-sites,abdullahsalem/foundation-sites,denisahac/foundation-sites