[CIVIS-9278] Dogfood quality-gates in the CI

[ManuelPalenzuelaDD]

This patch adds quality gates to the CI. All rules will be non-blocking

What and why?

Quality gates is a new Datadog product. It allows for creating rules that will be evaluated during the CI process (it will block CI pipelines if there are code issues, e.g. new flaky tests).

We are testing a new code coverage rule that will fail if the code coverage of a feature branch decreases by more than a threshold compared to the default branch. It'd be very useful to also test this rule in this repo as it reports code coverage.

This patch integrates quality-gates into the CI, while marking the job as allowed_to_fail, meaning that quality-gates will never block the CI.

How?

Adding a new stage to the CI pipeline that runs quality-gates.

Review checklist

• Feature or bugfix MUST have appropriate tests (unit, integration)
• Make sure each commit and the PR mention the Issue number or JIRA reference
• Add CHANGELOG entry for user facing changes

Custom CI job configuration (optional)

• Run unit tests for Core, RUM, Trace, Logs, CR and WVT
• Run unit tests for Session Replay
• Run integration tests
• Run smoke tests
• Run tests for tools/