S allius/issue205 (#207)

* Add SolarmanEmu class

* Forward a device ind to establish the EMU connection

* Move SolarmanEmu class into a dedicated file

* Add cloud connection counter

* Send inverter data in emulator mode

* Improve emulator mode

- parse more values from MQTT register
- differ between inverter and logger serial no

* Add some unit tests for SolarmanEmu class

* Send seconds since last sync in data packets

* Increase test coverage

app/src/gen3plus/inverter_g3p.py

@@ -3,13 +3,18 @@ from asyncio import StreamReader, StreamWriter
 if __name__ == "app.src.gen3plus.inverter_g3p":
     from app.src.inverter_base import InverterBase
     from app.src.gen3plus.solarman_v5 import SolarmanV5
+    from app.src.gen3plus.solarman_emu import SolarmanEmu
 else:  # pragma: no cover
     from inverter_base import InverterBase
     from gen3plus.solarman_v5 import SolarmanV5
+    from gen3plus.solarman_emu import SolarmanEmu
 
 
 class InverterG3P(InverterBase):
     def __init__(self, reader: StreamReader, writer: StreamWriter,
                  client_mode: bool = False):
+        remote_prot = None
+        if client_mode:
+            remote_prot = SolarmanEmu
         super().__init__(reader, writer, 'solarman',
-                         SolarmanV5, client_mode)
+                         SolarmanV5, client_mode, remote_prot)