dev(narugo): add unittest for blob url loading

import pathlib

import pytest

from PIL import Image

        actual_image = load_image(url, mode='RGB', force_background='white')

        expected_image = load_image(local_image_file, mode='RGB', force_background='white')

        assert image_diff(actual_image, expected_image, throw_exception=False) < 1e-2

    @pytest.mark.parametrize(['filename'], [

        ('mostima_post.jpg',),

        ('genshin_post.jpg',),

        ('nian_640.png',),

    ])

    def test_load_image_from_blob_url(self, filename, image_diff):

        actual_image = load_image(

            pathlib.Path(get_testfile(f'{filename}_blob.txt')).read_text().strip(),

            mode='RGB', force_background='white'

        )

        expected_image = load_image(

            get_testfile(filename),

            mode='RGB', force_background='white'

        )

        assert image_diff(actual_image, expected_image, throw_exception=False) < 1e-2