Add support for enabling autoscaling

[vboulineau]

What this PR does / why we need it:

Add support for enabling autoscaling

Which issue this PR fixes

Special notes for your reviewer:

Variable is not yet documented on purpose. Once datadog-crds chart is merged, we need to upgrade again the deps in datadog-operator and datadog-agent

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [x] Chart Version bumped
• [x] Documentation has been updated with helm-docs (run: .github/helm-docs.sh)
• [x] CHANGELOG.md has been updated
• [x] Variables are documented in the README.md
• [x] For Datadog Operator chart or value changes update the test baselines (run: make update-test-baselines)

[vboulineau]

Looks good. could you add a scenario in https://github.com/DataDog/helm-charts/tree/main/charts/datadog/ci to validate that the option is working?

Added