getMessages method

Will get a collection of PcoPeopleMessage objects (expecting many) using a path like this: https://api.planningcenteronline.com/people/v2/message_groups/1/messages

Implementation

Future<PcoCollection<PcoPeopleMessage>> getMessages(
    {PcoPeopleMessageQuery? query}) async {
  query ??= PcoPeopleMessageQuery();
  var url = '$apiEndpoint/messages';
  return PcoCollection.fromApiCall<PcoPeopleMessage>(url,
      query: query, apiVersion: apiVersion);
}