the properties to query.
the name of the property to query.
the default value of the property.
The value of the property, or default_value if it is not set or not a string property.
Threadsafety: It is safe to call this function from any thread, although the data returned is not protected and could potentially be freed if you call SDL_SetPointerProperty or SDL_ClearProperty on these properties from another thread. If you need to avoid this, use SDL_LockProperties and SDL_UnlockProperties.
Get a string property from a group of properties.