Performance and code improvements

[wapcrazut]

I saw that the scrapping speed was quite slow and took the opportunity to improve some things:

• Remove creating multiple browsers.
• Remove opening and closing multiple pages.
• Reject loading CSS, fonts, and images.
• Allow async video download.
• Only download the final project if the course has one.
• Improve logging to see the progress.

[ReneR97]

Hey, thanks for the work you did.