chore: update pin, exti, delay

fix: fifo has to be volatile

feat: implement usb devicd cdc descriptors, init, setup

feat: move all sending instructions to generic send functions

fix: make sure to error if endpoint id not found in interrupt

This generally shouldn't happen,
but it needs to be ensured that the
memory at incorrect place won't be read
or written to!
Otherwise there could be undefined behavior!
This would possibly write to the fifos,
meaning the data the usb sends could be
different than what the application intended!

feat: implement most of enumeration

feat: receive setup packets

wip: usb

feat: add registers, pin, exti, usb_device skeleton