usqlite on a pico 2350

[PaulJBarter]

Thanks @spatialdude for this implementation. It took a bit of faffing about (mostly because I'd never built a uf2 before), but I was able to implement this on a pi pico 2350. For some reason I never got it to compile properly on a 2040 despite seeing that it was possible. Perhaps the extra SRAM and memory on the 2350 made a difference.
As a suggestion, I think it would help others if you posted a working .uf2 for some of the common builds (e.g. pi pico RP2040). It won't necessarily be the latest micropython version, but if it works on a pico, that would help others like me to get started. I'm also happy to post the pico 2350 .uf2 (for MicroPython v1.26.0) if others would benefit from my lost hours trying to get this done.
Thanks again.