Pico all compat

[peardox]

This (somwhat longer than desired) version enables compatibility with pico, pico w and pico 2

Basically the LED stuff is split out and calls are made rather than directly accessing pins

This version decides what to build based in the CMakeLists.txt - and command-line e.g. -DPICO_BOARD=pico_w will build for a W

Specifically PICO_DEFAULT_LED_PIN doesn't work on a Pico W as it's pin is via the CYW43

I had problems getting pico2 to run from command but that's the toolchain I was checking with. When build via VSCode it does fine with pico2

It also appears as you've MAY HAVE a specific SDK - had problems until I repaced pico-sdk with a fresh one (that family_example stuff was driving me crazy - appears to be old stuff)

Checked resulting u2f's against all devices (pico, pico w, + pico 2)