sendSystemMessage function
Sends the System message to the recipientId via API request
The recipient will receive this system message through the chat connection as
the common system message.
properties - the additional parameters that the recipient will receive in the CubeMessage.properties
Implementation
Future<CubeMessage> sendSystemMessage(int recipientId, Map<String, String>? properties) {
return SendSystemMessageQuery(recipientId, properties).perform();
}