Pico Debug Versions Save

The prior code had the best intentions by sizing the HID IN response to be the same as the OUT message, but this was a flawed approach. In theory, the PC side software should always follow the HID Report Descriptor size of 64 bytes, so the response would happen to be the same (and be of the correct size). However, some IDE software (Linux only) did not do this, and so the response was under-sized. The IDE would give a cryptic error message and the user was none the wiser as to what went wrong.

Operation remains unchanged from v10.02, but there is now a unique serial number in the USB descriptor and in the CMSIS-DAP DAP_Info response.

This addition helps with users who have multiple devices that are running pico-debug at the same time.

This leverages a new PLL configuration so as to co-exist more easily with pico-sdk

There are now two versions to appeal to different users; see the README.md for the description.