Finds the most suitable OS-provided folder for @p folder, and returns its path in OS-specific notation.
char* SDL_GetPath(SDL_Folder folder);
Returns Either a null-terminated C string containing the full path to the folder, or NULL if an error happened.
Many OSes provide certain standard folders for certain purposes, such as storing pictures, music or videos for a certain user. This function gives the path for many of those special locations.
Note that the function is expensive, and should be called once at the beginning of the execution and kept for as long as needed.
The returned value is owned by the caller and should be freed with SDL_free().
If NULL is returned, the error may be obtained with SDL_GetError().