auto ConvertToExternal(const ImageBundle& ib, size_t bits_per_sample, bool float_out, size_t num_channels, JxlEndianness endianness, size_t stride_out, ThreadPool* thread_pool, void* out_image, size_t out_size, const PixelCallback& out_callback, jxl::Orientation undo_orientation, bool unpremul_alpha) -> Status