zephyr/modusocket: Implement recv() for UDP sockets.
zephyr/modusocket: Implement recv() for UDP sockets.

The foundation of recv() support is per-socket queue of incoming packets,
implemented using Zephyr FIFO object. This patch implements just recv()
for UDP, because TCP recv() requires much more fine-grained control of
network fragments and handling other issues, like EOF condition, etc.

chrisdearman/micropython,hiway/micropython,deshipu/micropython,lowRISC/micropython,cwyark/micropython,ryannathans/micropython,AriZuu/micropython,chrisdearman/micropython,tralamazza/micropython,trezor/micropython,adafruit/circuitpython,blazewicz/micropython,PappaPeppar/micropython,pfalcon/micropython,kerneltask/micropython,adafruit/circuitpython,Peetz0r/micropython-esp32,lowRISC/micropython,HenrikSolver/micropython,kerneltask/micropython,pramasoul/micropython,PappaPeppar/micropython,AriZuu/micropython,micropython/micropython-esp32,alex-robbins/micropython,TDAbboud/micropython,torwag/micropython,trezor/micropython,cwyark/micropython,toolmacher/micropython,trezor/micropython,torwag/micropython,selste/micropython,tralamazza/micropython,MrSurly/micropython-esp32,lowRISC/micropython,tobbad/micropython,kerneltask/micropython,chrisdearman/micropython,infinnovation/micropython,blazewicz/micropython,toolmacher/micropython,PappaPeppar/micropython,MrSurly/micropython,ryannathans/micropython,adafruit/micropython,puuu/micropython,alex-robbins/micropython,toolmacher/micropython,bvernoux/micropython,trezor/micropython,oopy/micropython,Timmenem/micropython,henriknelson/micropython,adafruit/circuitpython,tobbad/micropython,bvernoux/micropython,MrSurly/micropython,micropython/micropython-esp32,cwyark/micropython,swegener/micropython,selste/micropython,MrSurly/micropython,chrisdearman/micropython,MrSurly/micropython,SHA2017-badge/micropython-esp32,puuu/micropython,MrSurly/micropython,dmazzella/micropython,deshipu/micropython,deshipu/micropython,adafruit/micropython,Peetz0r/micropython-esp32,pramasoul/micropython,alex-robbins/micropython,MrSurly/micropython-esp32,HenrikSolver/micropython,blazewicz/micropython,TDAbboud/micropython,pozetroninc/micropython,MrSurly/micropython-esp32,MrSurly/micropython-esp32,micropython/micropython-esp32,henriknelson/micropython,bvernoux/micropython,infinnovation/micropython,deshipu/micropython,Peetz0r/micropython-esp32,pfalcon/micropython,selste/micropython,HenrikSolver/micropython,oopy/micropython,blazewicz/micropython,PappaPeppar/micropython,trezor/micropython,AriZuu/micropython,MrSurly/micropython-esp32,SHA2017-badge/micropython-esp32,infinnovation/micropython,oopy/micropython,adafruit/circuitpython,alex-robbins/micropython,Timmenem/micropython,adafruit/circuitpython,puuu/micropython,adafruit/micropython,selste/micropython,hiway/micropython,pramasoul/micropython,infinnovation/micropython,pozetroninc/micropython,torwag/micropython,bvernoux/micropython,Timmenem/micropython,swegener/micropython,pozetroninc/micropython,tobbad/micropython,hiway/micropython,Timmenem/micropython,cwyark/micropython,adafruit/micropython,swegener/micropython,torwag/micropython,swegener/micropython,kerneltask/micropython,hiway/micropython,lowRISC/micropython,tobbad/micropython,tralamazza/micropython,tobbad/micropython,pfalcon/micropython,kerneltask/micropython,AriZuu/micropython,alex-robbins/micropython,hiway/micropython,swegener/micropython,pfalcon/micropython,Peetz0r/micropython-esp32,torwag/micropython,pramasoul/micropython,adafruit/circuitpython,puuu/micropython,infinnovation/micropython,PappaPeppar/micropython,ryannathans/micropython,tralamazza/micropython,cwyark/micropython,Peetz0r/micropython-esp32,puuu/micropython,blazewicz/micropython,AriZuu/micropython,dmazzella/micropython,pozetroninc/micropython,dmazzella/micropython,ryannathans/micropython,adafruit/micropython,deshipu/micropython,oopy/micropython,micropython/micropython-esp32,toolmacher/micropython,bvernoux/micropython,henriknelson/micropython,lowRISC/micropython,toolmacher/micropython,SHA2017-badge/micropython-esp32,henriknelson/micropython,micropython/micropython-esp32,TDAbboud/micropython,henriknelson/micropython,pramasoul/micropython,HenrikSolver/micropython,TDAbboud/micropython,SHA2017-badge/micropython-esp32,ryannathans/micropython,pfalcon/micropython,pozetroninc/micropython,TDAbboud/micropython,oopy/micropython,SHA2017-badge/micropython-esp32,dmazzella/micropython,Timmenem/micropython,HenrikSolver/micropython,selste/micropython,chrisdearman/micropython