use geocoder lookup fallback when autocomplete returns zero results

[rrgrs]

Summary

I was having issues where users were copy and pasting addresses that contained "subpremise elements" in them (e.g. apartment number or unit number) which was causing the autocomplete to return zero results. To solve this I decided to implement a fallback to the geocoder service when there are no results from autocomplete, which will then give results when subpremise elements exist within the autocomplete text input.