createConversation method
Implementation
Future<JMConversationInfo> createConversation({
required dynamic target, //(JMSingle | JMGroup | JMChatRoom)
}) async {
Map param = target.toJson();
Map resJson = await _channel.invokeMethod('createConversation',
param..removeWhere((key, value) => value == null));
return JMConversationInfo.fromJson(resJson);
}