Renamed SDL_Get/SetProperty() to SDL_Get/SetPointerProperty()

This is consistent with the naming for the functions that affect other data types

Fixes https://github.com/libsdl-org/SDL/issues/10241

include/SDL3/SDL_iostream.h

@@ -395,9 +395,6 @@ extern SDL_DECLSPEC int SDLCALL SDL_CloseIO(SDL_IOStream *context);
  *          SDL_GetError() for more information.
  *
  * \since This function is available since SDL 3.0.0.
- *
- * \sa SDL_GetProperty
- * \sa SDL_SetProperty
  */
 extern SDL_DECLSPEC SDL_PropertiesID SDLCALL SDL_GetIOProperties(SDL_IOStream *context);