Update victron_mqtt to 2025.8.20 and merge topics (#87)

Co-authored-by: tomer-w <57483589+tomer-w@users.noreply.github.com>

Author: github-actions[bot]

custom_components/victron_mqtt/manifest.json

@@ -11,13 +11,13 @@
   "iot_class": "local_push",
   "issue_tracker": "https://github.com/tomer-w/ha-victron-mqtt/issues",
   "requirements": [
-    "victron_mqtt==2025.8.19"
+    "victron_mqtt==2025.8.20"
   ],
   "ssdp": [
     {
       "manufacturer": "Victron Energy",
       "X_MqttOnLan": "1"
     }
   ],
-  "version": "2025.8.15"
+  "version": "2025.8.16"
 }