Add DAST security report CI job

Add DAST security report CI job

Part of https://gitlab.com/gitlab-org/gitter/webapp/issues/2118

Previous MR that enabled other security report jobs, https://gitlab.com/gitlab-org/gitter/webapp/merge_requests/1375

Dev notes

Accessing a Docker container service from another container service (hosts and network),

• gitlab-org/gitlab-selenium-server#1
• gitlab-org/gitlab-runner#1042 (closed)
  • gitlab-org/gitlab-runner#1042 (comment 144420147)

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Pass variables to services,

• https://docs.gitlab.com/ee/ci/docker/using_docker_images.html#passing-environment-variables-to-services
• https://docs.gitlab.com/ee/ci/services/mysql.html
• gitlab-org/gitlab-runner#1809 (closed)
• gitlab-org/gitlab-runner#2341
• gitlab-org/gitlab-runner#3808
• gitlab-org/gitlab#19561