Additional address fields #441

With providers that return accuracy information the list of address results without the accuracy information I find to not be completely useful.

For instance, the ArcGIS service I'm using can return results matched at different levels and with different accuracies within those levels. I'd like to choose a point/rooftop match over a postal code/approximated match and a 99% street match over a 70%, etc.

If I put together a PR for this do you have any thoughts on how you'd like to see it implemented? Would you accept an extension of the address model? Maybe a custom data property with key value pairs that can be utilized by individual providers?