Port of STM32WLxx example for RAK3172

16 July 2022: HEADS UP - may-queen branch will be a 'clean' / sparsely-filled LoRaWAN End Node project without most of the example code for Nucleo buttons. The BSP will be renamed, too. After some testing, this will merge into master.

Quick update to V1.2 of ST firmware package; unit tested as a Class C mote

Update 14 July 2022: Reviewed merge of V1.2 ST FW and found a number of issues, mostly in the lora_app.c merge. I think I've fixed battery level reporting. Cleaned-up LED control code (though LEDs don't have a clear functionality, this could use some more app-specific attention). Added implementation of v1.0.4. Moved GPIO initialization to match ST LoRa_End_Node example. Unit-tested in Class C and Class A. Changed some defaults in the IOC file (use ST-provided EUI, v1.0.4, Class A, debugger disabled). I'm happy to merge PRs with different defaults when there's enough user request.

As usual, this is provided with zero warranty for usefulness or reliability.