getApp method
Will get a collection of PcoPeopleApp objects (expecting one)
using a path like this: https://api.planningcenteronline.com/people/v2/people/1/person_apps/1/app
Implementation
Future<PcoCollection<PcoPeopleApp>> getApp({PcoPeopleAppQuery? query}) async {
query ??= PcoPeopleAppQuery();
var url = '$apiEndpoint/app';
return PcoCollection.fromApiCall<PcoPeopleApp>(url,
query: query, apiVersion: apiVersion);
}