Add the possibility to link address part fields to an address webform element

Problem/Motivation

One of our CiviCRM forms has an address field that's split up in street, street_number, box, postal_code and city fields. In Webform, an address field is a composite element, which basically means that it's 1 element with a bunch of sub elements. Currently, it doesn't seem to be possible to link CiviCRM fields with these sub elements.