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/tests/test_infos_g3p.py

@@ -110,7 +110,7 @@ def test_parse_4210(inverter_data: bytes):
 
     assert json.dumps(i.db) == json.dumps({
          "controller": {"Sensor_List": "02b0", "Power_On_Time": 2051}, 
-         "inverter": {"Serial_Number": "Y17E00000000000E", "Version": "V4.0.10", "Rated_Power": 600, "BOOT_STATUS": 0, "DSP_STATUS": 21930, "Max_Designed_Power": 2000, "Output_Coefficient": 100.0}, 
+         "inverter": {"Serial_Number": "Y17E00000000000E", "Version": "V4.0.10", "Rated_Power": 600, "BOOT_STATUS": 0, "DSP_STATUS": 21930, "Work_Mode": 0, "Max_Designed_Power": 2000, "Input_Coefficient": 100.0, "Output_Coefficient": 100.0}, 
          "env": {"Inverter_Status": 1, "Detect_Status_1": 2, "Detect_Status_2": 0, "Inverter_Temp": 14}, 
          "events": {"Inverter_Alarm": 0, "Inverter_Fault": 0, "Inverter_Bitfield_1": 0, "Inverter_bitfield_2": 0},
          "grid": {"Voltage": 224.8, "Current": 0.73, "Frequency": 50.05, "Output_Power": 165.8}, 
@@ -119,7 +119,8 @@ def test_parse_4210(inverter_data: bytes):
                    "pv3": {"Voltage": 34.6, "Current": 1.89, "Power": 65.5, "Daily_Generation": 0.05, "Total_Generation": 31.89}, 
                    "pv4": {"Voltage": 1.7, "Current": 0.01, "Power": 0.0, "Total_Generation": 15.58}}, 
          "total": {"Daily_Generation": 0.11, "Total_Generation": 101.36},
-         "inv_unknown": {"Unknown_1": 512}
+         "inv_unknown": {"Unknown_1": 512},
+         "other": {"Output_Shutdown": 65535, "Rated_Level": 3, "Grid_Volt_Cal_Coef": 1024}
         })
 
 def test_build_4210(inverter_data: bytes):