Unify GetHostname() and use libuv implementation (#1391)

cscore/src/main/native/cpp/cscore_cpp.cpp

@@ -8,6 +8,7 @@
 #include "cscore_cpp.h"
 
 #include <wpi/SmallString.h>
+#include <wpi/hostname.h>
 
 #include "Handle.h"
 #include "Log.h"
@@ -686,4 +687,6 @@ wpi::ArrayRef<CS_Sink> EnumerateSinkHandles(wpi::SmallVectorImpl<CS_Sink>& vec,
   return Sinks::GetInstance().GetAll(vec);
 }
 
+std::string GetHostname() { return wpi::GetHostname(); }
+
 }  // namespace cs