Added empty array instead of null return for api v2. Api v1 returns null

that's really to mimic the old importer logic shown here: https://github.com/GovWizely/webservices/pull/62/files#diff-93f104713f13867cec4c0385d4fa93f6L40
if the array was empty it sets it as null. I thought we crush backward compat if return an empty array where null was returned before