S allius/issue334 (#335)

* move forward_at_cmd_resp into InfosG3P class

- the variable is shared between the two connections
of an inverter. One is for the TSUN cloud and the
other for the device.

* use inverter class to share values between
the two protocol instances of a proxy
- move forward_at_cmd_resp into class InverterG3P
- store inverter ptr in Solarman_V5 instances
- add inverter ptr to all constructurs of protocols
- adapt doku and unit tests-
- add integration tests for AT+ commands which
  check the forwarding from and to the TSUN cloud

* adapt and improve the unit tests
- fix node_id declaration, which always has a / at
  the end. See config grammar for this rule
- set global var test to default after test run

app/src/gen3plus/solarman_emu.py

@@ -10,11 +10,12 @@ logger = logging.getLogger('msg')
 
 
 class SolarmanEmu(SolarmanBase):
-    def __init__(self, addr, ifc: "AsyncIfc",
+    def __init__(self, inverter, addr, ifc: "AsyncIfc",
                  server_side: bool, client_mode: bool):
         super().__init__(addr, ifc, server_side=False,
                          _send_modbus_cb=None,
                          mb_timeout=8)
+        _ = inverter
         logging.debug('SolarmanEmu.init()')
         self.db = ifc.remote.stream.db
         self.snr = ifc.remote.stream.snr