Add locations-navigation widget 71258834

For single domain websites, there needs to be a widget that will populate a navigation to all their sub locations.

Traditionally this would be fly out activated on hover (desktop), and double tap for mobile. However, as we transition away from many hover state interections, I'm wondering if we activate this on click instead? Also, the parent element delivers users to a page with all locations, whereas a child would deliver them to a location or an area page. Here is an example of said functionality: http://www.pacificaseniorliving.com/.

Related PR: https://github.com/G5/g5-content-management-system/pull/362

This branch is deployed to http://g5-wg-locations-navigation.herokuapp.com