Revert "Simplify `read_data_at_url` in youtube_download.py"

This reverts commit ab0bc8040ed76aedb9caba99994d5bb4ad95c49c.

Conflicts:
	youtube_download.py
Add callback argument to `read_data_at_url` in youtube_download.py
Add `--chunks-size` argument and print progress in youtube_download.py