Description:

This PR enables decoding WiPhone LoRa packets.
WiPhone uses the RadioHead library which adds some extra bytes to the header, but is currently unused (as per default 0xFFFF0000).

The format is as followed:

  uint8_t rh_to; // currently 0xff
  uint8_t rh_from; // currently 0xff
  uint8_t rh_id; // currently 0x00
  uint8_t rh_flags; // currently 0x00
  uint16_t magic; // always 0x6c6d
  uint32_t to; // ESP ChipID or 0x00000000 for "broadcast"
  uint32_t from; // ESP ChipID
  char message[230];

I modified the LoRa to support more devices in the future, but I would like to see a mechanism similar as used in the rtl_433_ESP library;
Then again, this library does support the sx127x chipset (that also does LoRa) already, it only doesn't support the RFM9xW.

Sending a message would be as simple as:
mosquitto_pub -h 127.0.0.1 -t "home/OpenMQTTGateway_ESP32_LORA/commands/MQTTtoLORA" -m '{"type":"WiPhone","from":"C0FFEE","to":"0","message":"Hello from OMG"}'

Incoming messages will look like:
home/OpenMQTTGateway_ESP32_LORA/LORAtoMQTT {"rssi":-113,"snr":5.5,"pferror":18748,"packetSize":34,"from":"123456","to":"000000","message":"hi from wiphone","type":"WiPhone"}

Checklist:

• The pull request is done against the latest development branch
• Only one feature/fix was added per PR and the code change compiles without warnings
• I accept the DCO.

Notes:

To be honest, I'm not sure if people want to have the LoRa library extended to support decoding different payloads, but I thought it was the right thing to do (I came across this library which had all the fantastic features I needed, except LoRa payload decode support).

Also:

• When non-ascii data arrives, it converts to hex and will put the data in LORAdata["hex"] (and the other way around)
• I used the conversion methods from Taken from main/ZgatewaySRFB.ino, but it might be better to have a helper class that one could use to do these conversions.
• I also added invertIQ support for downstream/multiple gateway support

Let me know what you think.
Cheers.