refactor(Core/Common): generalise platform specific includes in common/Platform (#5058)

src/common/Platform/ServiceWin32.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2016+     AzerothCore <www.azerothcore.org>, released under GNU GPL v2 license, you may redistribute it and/or modify it under version 2 of the License, or (at your option), any later version.
+ * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
+ * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
+ */
+
+#ifdef _WIN32
+#ifndef _WIN32_SERVICE_
+#define _WIN32_SERVICE_
+
+bool WinServiceInstall();
+bool WinServiceUninstall();
+bool WinServiceRun();
+
+#endif                                                      // _WIN32_SERVICE_
+#endif                                                      // _WIN32