Use Trafilatura for boilerplate removal

[DavidNemeskey]

JusText seems to remove too much and its accuracy seems not to be very high. We need a better tool for boilerplate removal.

Options:

• BoilerNet
• web2text
• Trafilatura
• a new, custom tool

The first two options (and the last one as well, probably) use DL, and need training data. For now, let's experiment with Trafilatura.