Complete a CTRT rewrite of the job artifacts doc

The job artifacts page is one of our most visited pages, and is in need of a CTRT cleanup. This issue will track the work done as part of the effort.

Required work:

Standard CTRT cleanup
Remove screenshots, use SVGs instead, validate all UI text is still accurate.
Move file from doc/ci/pipelines/job_artifacts.md to doc/ci/jobs/job_artifacts.md for more logical IA.
The troubleshooting section could go on its own page. Our guidance is to do this if there are more than 5 troubleshooting sections.
Update nav to match
Make downloading and browsing artifacts two separate tasks, and give the difference between downloading reports vs other artifacts. See #391443 (comment 1275812832)
~~Incorporate the fixes from !115826 (closed) into the updated page.~~

Edited Apr 12, 2023 by Marcel Amirault