Add container_scanning for starboard configuration as an alternative
This MR adds alternative keyword container_scanning
to be used to configure Operational Vulnerabilities. We were using starboard
keyword instead, and we will continue to support it and we will finally remove it in GitLab %16.0.
After this MR is merged we will continue work to rename module internally to better reflect current purposes.
Related to gitlab-org/gitlab#368828 (closed)
Edited by Alan (Maciej) Paruszewski