modified picow access point example to use lwip http server

[Louis31423142]

[lurch]

I've not tested this myself, but it looks pretty good to my eyes :+1:

[peterharperuk]

This is good. But it's broken the captive portal functionality. I think this is an issue with the makefsdata.py tool. I'll assign an issue which you could have a go at fixing?

[peterharperuk]

See https://github.com/raspberrypi/pico-sdk/issues/2646