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/gen3/talent.py

@@ -34,10 +34,11 @@ class Control:
 class Talent(Message):
     TXT_UNKNOWN_CTRL = 'Unknown Ctrl'
 
-    def __init__(self, addr, ifc: "AsyncIfc", server_side: bool,
+    def __init__(self, inverter, addr, ifc: "AsyncIfc", server_side: bool,
                  client_mode: bool = False, id_str=b''):
         super().__init__('G3', ifc, server_side, self.send_modbus_cb,
                          mb_timeout=15)
+        _ = inverter
         ifc.rx_set_cb(self.read)
         ifc.prot_set_timeout_cb(self._timeout)
         ifc.prot_set_init_new_client_conn_cb(self._init_new_client_conn)