Use Gotenberg instead of wkhtmltopdf

[sanbor]

wkhtmltopdf project has been archive more than 3 years ago: https://github.com/wkhtmltopdf/wkhtmltopdf

openhtmltopdf maintained fork doesn't work because of the requirement to execute JS.

There is a well maintained and Docker friendly project called Gotenberg we could use to generate html/pdf reports.