Implement KDNET driver for debugging over network

There is some preliminary work by hpoussin on implementing kdnet/kdstub:

• https://github.com/reactos/reactos/commits/freeldr_kdnet_kdstub

There is also a 3rd party project that allows using patched kdnet.dll from Windows 8.1 or 10 on older systems, such as Windows XP or 2003 (and so ReactOS), however it's limited to 32-bit x86 architecture:

• https://github.com/MovAX0xDEAD/KDNET

Since 734cd5e we've got HAL support required for it to work (see CORE-17360).

Our wiki documents how to set up ReactOS debugging over network: https://reactos.org/wiki/Debugging#Network

Once our own KDNET support will be in place, it will be possible to make custom NIC extension drivers for it, e.g. CORE-18223.