SOC_U: Preliminary implementation of sockets.

Stubbed CreateMemoryBlock

Using Berkeley sockets, and Winsock2.2 on Windows.
So far ftpony creates the socket and accepts incoming connections

SOC_U: Renamed functions to maintain consistency

Also prevents possible scope errors / conflicts with the actual Berkeley socket functions

SOCU: Close all the opened sockets when cleaning up SOCU

src/core/hle/service/soc_u.h

@@ -14,6 +14,7 @@ namespace SOC_U {
 class Interface : public Service::Interface {
 public:
     Interface();
+    ~Interface();
 
     std::string GetPortName() const override {
         return "soc:U";