* 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
