getCarriers method
Will get a collection of PcoPeopleCarrier objects (expecting many)
using a path like this: https://api.planningcenteronline.com/people/v2/carriers
Implementation
Future<PcoCollection<PcoPeopleCarrier>> getCarriers(
{PcoPeopleCarrierQuery? query}) async {
query ??= PcoPeopleCarrierQuery();
var url = '$apiEndpoint/carriers';
return PcoCollection.fromApiCall<PcoPeopleCarrier>(url,
query: query, apiVersion: apiVersion);
}