getDesignations method

Will get a collection of PcoGivingDesignation objects (expecting many) using a path like this: https://api.planningcenteronline.com/giving/v2/donations/1/designations

Implementation

Future<PcoCollection<PcoGivingDesignation>> getDesignations(
    {PcoGivingDesignationQuery? query}) async {
  query ??= PcoGivingDesignationQuery();
  var url = '$apiEndpoint/designations';
  return PcoCollection.fromApiCall<PcoGivingDesignation>(url,
      query: query, apiVersion: apiVersion);
}