Auto DevOps support for Group Security Dashboard

What does this MR do?

Add a new job sast_dashboard to Auto DevOps in order to support the Group Security Dashboard using the required reports syntax.

The old job guarantees backward compatibility with the existing features for runners <11.5. This change will be improved when the old syntax will be dropped (12.0).

Users can disableold or new reports jobs by setting OLD_REPORTS_DISABLED or NEW_REPORTS_DISABLED variables.

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/54160

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.