Add semihosting support for nrf52 devices (#4137)

* Turn off vscode cmake prompt - we don't use cmake on meshtastic

* Add rak4631_dap variant for debugging with NanoDAP debug probe device.

* The rak device can also run freertos (which is underneath nrf52 arduino)

* Add semihosting support for nrf52840 devices
Initial platformio.ini file only supports rak4630
Default to non TCP for the semihosting log output for now...
Fixes https://github.com/meshtastic/firmware/issues/4135

* fix my botched merge - keep board_level = extra flag for rak3631_dbg

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

boards/wiscore_rak4631.json

@@ -35,7 +35,7 @@
     "svd_path": "nrf52840.svd",
     "openocd_target": "nrf52840-mdk-rs"
   },
-  "frameworks": ["arduino"],
+  "frameworks": ["arduino", "freertos"],
   "name": "WisCore RAK4631 Board",
   "upload": {
     "maximum_ram_size": 248832,