Moved raw input event processing from the main thread to the joystick thread

This allows fast joystick event delivery regardless of what the main thread is doing.

include/SDL_config_windows.h

@@ -215,7 +215,9 @@ typedef unsigned int uintptr_t;
 /* Enable various input drivers */
 #define SDL_JOYSTICK_DINPUT 1
 #define SDL_JOYSTICK_HIDAPI 1
+#ifndef __WINRT__
 #define SDL_JOYSTICK_RAWINPUT   1
+#endif
 #define SDL_JOYSTICK_VIRTUAL    1
 #ifdef SDL_WINDOWS10_SDK
 #define SDL_JOYSTICK_WGI    1