Implement Tin Can tracking in Moodle Quiz

I'd like to add Tin Can tracking to the Moodle quiz. ideally I'd like to do this as part of core, but I'm open to suggestions of how this can be achieved via a plugin.

I've made a start here: https://github.com/garemoko/moodle_tincan_quiz/commit/a62ee517c59696fc8164ddf850711a375b50fb32

See also https://tracker.moodle.org/browse/MDL-35433