Fix a typo and correct the directory path when auto downloading dataset

[SamWang0807]

In dataset_preparation.py, the path that stores the downloaded dataset should be under "final_path", instead of "extract_to".
Also, import path of "custom_logger" function typo is fixed.

• The code follows the Python style guide.
• Code and files are well organized.
• All tests pass.
• New code is covered by tests.
• We would be very happy if gitmoji😆 could be used to assist the commit message💬!

[henrytsui000]

Hi Sam,

Thank you for your contributions! I've reviewed the changes and they look good to me. All tests are passing, which is great. I'll proceed with merging this PR.

Thanks again for your attention to detail and your efforts!

Best regards,
Henry Tsui