feat: Add support for modsecurity secruleengine configuration

In support of gitlab-org/gitlab#8558 (closed), this MR adds support for passing AUTO_DEVOPS_MODSECURITY_SEC_RULE_ENGINE to the underlying chart to customize execution of modsecurity within the ingress nginx configuration.

This configuration is enabled as "DetectionOnly" by default within the nginx-controller ConfigMap but overridable per ingress resource. This allows customization of the specific handling of the ruleset, in this case enabling the engine to be toggled to "Off" or "On" to either disable rulechecks entirely or enable blocking mode.

This MR is paired with gitlab-org/charts/auto-deploy-app!12 (merged) which adds the necessary fields to the chart