Improve reporting so that development teams can act on the test results in staging

We currently rely on a rotation to triage and debug tests in staging.

After completing the enterprise test gaps, we will have ~200 more tests in GitLab QA. We need to improve our process so that each test suite in each area is visible and test coverage can be co-owned and digested by every team in development.

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Task:

• Create a new job for each Stage that includes only the JUnit results for that Stage: https://gitlab.com/gitlab-org/quality/team-tasks/issues/316