BLE, TCP and UDP Support

[Scavanger]

Adds support for wireless connections.

Bluetooth Low Energy:
Hardware:

• CC2541 based modules like HM1X/HC08/09
• Nordic Semiconductor NRF (Adafruit BLE Shield)
• SpeedyBee adapters

For CC2541 based modules a small hack in iNav is necessary: iNavFlight/inav#7931
See also: iNavFlight/inav#7783

TCP and UDP
See discussion here: #1436

I have written a firmware for ESP8266 modules that allows easy configuration via a web interface.
It checks MSP frames for errors and wraps an MSP frame in one UDP/TCP packet.
UDP runs very smoothly, TCP is a bit laggy.
https://github.com/Scavanger/MSPWifiBridge
But any device that forwards the data of a UART one-to-one to TCP/UDP should work the same way.

if #1447/iNavFlight/inav#7812 is merged, this PR/iNavFlight/inav#7931 may needs a rebase.

[DzikuVx]

@Scavanger this is a great PR. But we have to change how it's done. I've left a review in the INAV repo but it ultimately goes down to:

1. Leave MSP2_INAV_LOGIC_CONDITIONS unchanged
2. Add MSP2_INAV_LOGIC_CONDITIONS_SINGLE frame
3. Switch configurator to use MSP2_INAV_LOGIC_CONDITIONS_SINGLE

And then, in one of future releases we can remove support for MSP2_INAV_LOGIC_CONDITIONS completely.

What do you think?

[Scavanger]

@DzikuVx

Yeah, this is the cleaner way.
Should the version check for firmwares < 5.0 remain in and then be switched back to MSP2_INAV_LOGIC_CONDITIONS if necessary?

[DzikuVx]

@Scavanger yes, we'd like for Configurator 5 to support INAV 4. So it should indeed check for supported message.
If this will be to time consuming or just too complex we can always say: sorry, we do not support older version. Your call

[DzikuVx]

@Scavanger could you please add a small doc here or in the firmware repo on how to use it? It would be awesome to have at least a short explanation of what's going on

[Scavanger]

@DzikuVx
iNavFlight/inav#7931

[EduardTheThird]

Tried this feature using this board, https://www.adafruit.com/product/2821,
running this code:
https://github.com/EduardTheThird/inav-configurator-ESP8266-WiFi-UART-transparent-bridge/blob/master/WiFiUartTransparentBridge/WiFiUartTransparentBridge.ino

Worked, thanks! I only had to change my baud rate to 57600.