Fix #11 - Onboard LED for pico_w not working

[Kintar]

This builds on the inclusion of the cygw43_arch_none library from the 0.2 release and makes the following changes:

• hardware/rp2040/prebuild.cmake
  • Add USING_CYW43 compiler definition (rather than PICO_W of some sort, in case other pico hardware uses this chip)
• hardware/rp2040/hardware.c
  • now initializes the cyw43 system if building for a pico_w
  • removes guard around init_onboard_led (see next point)
• hardware/rp2040/onboard_led.c
  • add conditional guards to swap out the appropriate functions for onboard LED access depending on pico variant
• cli/node_dev.c
  • remove pico_w specific guard against onboard LED

Built using both Windows 11 and MacOS Sonoma, tested on an official Raspberry Pi Pico W.

[Kintar]

Oh, and since I use JetBrains tools for most of my development I committed the .idea directory to ease the effort of other folks who use the same tools. Happy to nuke it and add to .gitignore if there's a reason you don't want it.