this removed the RelocatedProgram construction step from pio uses.
there's not all that much to be said for the extra step because the
origin can be set on the input program itself, and the remaining
information exposed by RelocatedProgram can be exposed from
LoadedProgram instead (even though it's already available on the pio_asm
programs, albeit perhaps less convenient). we do lose access to the
relocated instruction iterator, but we also cannot think of anything
this iterator would actually be useful for outside of program loading.

closes #1338

It was intended to allow changing baudrate on shared spi/i2c. There's no
advantage in using it for PWM or PIO, and makes it less usable because you have to
have `embassy-embedded-hal` as a dep to use it.

execution wraps around after the end of instruction memory and wrapping
works with this, so we may as well allow program loading across this
boundary. could be useful for reusing chunks of instruction memory.

the many individual sets aren't very efficient, and almost no checks
were done to ensure that the configuration written to the hardware was
actually valid. this adresses both of these.