extmod/network_wiznet5k_provided: Add wiznet ethernet modnetwork driver.

Originally based on stm32/modnwwiznet5k.
Uses the TCP stack running on the Wiznet controller.

Updated to newer wiznet driver (in submodule).
Adds support for W5100S
Supports defining hw pins in board config or dynamically set at runtime.
Sets a default MAC address in the random namespace from the unique board id.

Also includes modnwwiznet5k.c updates by @irinakim12 in micropython#8021, most notably bringing in DHCP support.