Allow for the use of external BLE modules(UART devices)

[theBASTI0N]

Allow for nRF52832 module to be used as a better BLE interface.

Example found at https://github.com/theBASTI0N/nrf52832_scanner

This means if someone has a spare ble tag like a Ruuvitag they can use that as the BLE interface. This would provide better sensitivity and range then what is seen in the built in BLE module found in the RPI.

Also this extends the ble2mqtt functionality past devices that have built in BLE to devices such as the:
Onion Omega family

Found at: https://onion.io/

[theBASTI0N]

External nRF52832 modules are supported if data packet is:

• channel, rssi, mac address, ble packet

The following firmware can be flashed to either a Ruuvitag or other nRF52832 module.
https://github.com/theBASTI0N/nrf52832_scanner