make Weasyprint css urls to be automatic ingested

[zcrt]

Is your feature request related to a problem? Please describe.
Generating a pdf-report in the new flow looks untendend.

Describe the solution you'd like
As I understood there should be CSS available for styling the pdf-report. I would like to have some documentation for enabling this.

Kat-version
1.14

[underdarknl]

The env var is:
WEASYPRINT_BASEURL It needs to be a http url accesible by Weasyprint's service to access the static files.
We are trying to work out a way of not needing this variable.

The default is http://127.0.0.1:80/ which might, or might not work based on whatever hosting or containerization solution is used for hosting Rocky.

[dekkers]

The default should be http://127.0.0.1:8000/, I have fixed this in #2373

I'm also working on a change to get rid of the need of WEASYPRINT_BASEURL.

[dekkers]

Submitted PR to django-weasyprint yesterday, this is currently blocked waiting for it to be reviewed, merged and a new version released