network: NIC spoof (#911)

## Link to GitHub Issue or related Pull Request, if one exists
#0

## Description of change
Spoof a valid NIC, so games can use a local server completely offline.
Previously this was impossible on macOS wine, or it required km-test
loopback adapter on Windows.

## Testing
Tested DDR (32bit/64bit) and SDVX on Windows 10 and macOS Tahoe.
Enabling -nicspoof and -icmphook connects to airgapped 127.0.0.1.

src/spice2x/CMakeLists.txt

@@ -616,6 +616,7 @@ set(SOURCE_FILES ${SOURCE_FILES}
         hooks/networkhook.cpp
         hooks/icmphook_net.cpp
         hooks/icmphook_iphlpapi.cpp
+        hooks/nicspoof.cpp
         hooks/powrprof.cpp
         #hooks/rom.cpp
         hooks/setupapihook.cpp