Switch to new Auckland council property search API

[LaurenceGA]

This PR migrates the address lookup functionality to use the new Auckland Council property search API endpoint (nextapi/property). Found this by looking at the search endpoint they use on the address lookup page.

Key changes:

• API goes from SOAP -> REST
• Simplified data structure to get rid of some old fields
• Added some HTTP status code check so we get better errors when this happens
• All tests updated to match new API contract

[rusq]

LGTM, thank you @LaurenceGA