docker: Fix and improve local testing of Jenkins for SWH
That MR enables to easily test the SWH configuration for Jenkins in a local testing instance.
Previously SWH jobs could not be executed locally due to permission issues between containers, a first commit fixes those.
A second commit enables to automatically trigger the SWH jobs configuration for Jenkins
when the Jenkins service is starting, so you can do a docker compose up
and gain some
time by not having to manually do that processing in the Jenkins Web UI.