rework mqtt api

src/mqtt_helper.py

@@ -61,10 +61,14 @@ class MQTT:
                                   transport="tcp")
         self.client.connect(host=self.host, port=self.port, keepalive=60)
 
-    def publish(self, message: str) -> None:
+    def publish(self, message: str, subtopic: str = "") -> None:
         """
         Publish a message
         :param message:
+        :param subtopic:
         :return:
         """
-        self.client.publish(self.topic, message, qos=self.qos, retain=self.retain)
+        if subtopic:
+            self.client.publish(f"{self.topic}/{subtopic}", message, qos=self.qos, retain=self.retain)
+        else:
+            self.client.publish(self.topic, message, qos=self.qos, retain=self.retain)