Added SDL_GameControllerSendEffect() and SDL_JoystickSendEffect() to allow applications to send custom effects to the PS4 and PS5 controllers

See testgamecontroller.c for an example of a custom PS5 trigger effect

src/joystick/SDL_sysjoystick.h

@@ -166,6 +166,9 @@ typedef struct _SDL_JoystickDriver
     SDL_bool (*HasLED)(SDL_Joystick *joystick);
     int (*SetLED)(SDL_Joystick *joystick, Uint8 red, Uint8 green, Uint8 blue);
 
+    /* General effects */
+    int (*SendEffect)(SDL_Joystick *joystick, const void *data, int size);
+
     /* Sensor functionality */
     int (*SetSensorsEnabled)(SDL_Joystick *joystick, SDL_bool enabled);