Make Junit reports accessible via the API
Problem to solve
JUnit reports are only accessible via the UI, which means reports in non-public pipelines can't be downloaded without authenticating via the UI.
Artifacts from individual jobs can be downloaded, but that is inefficient when a compiled report is required.
Quality will start using it immediately.
Add an API route to fetch test reports for a given pipeline.
Permissions and Security
Probably the same permissions used for access to pipelines themselves.
Add the route to the Pipelines API page
The JUnit report feature is currently off by default due to performance issues, which will be fixed in #37725
Until then the new API route should also be behind the same feature flag as the full feature.
It will require new tests in