Security Dashboard – Backend – Create feature flag and service

What does this MR do and why?

We are adding the new_security_dashboard_attribute_filters feature flag and we are create a service that takes security attribute filters and a namespace, and returns the list of project IDs that match those attributes by querying Security::ProjectToSecurityAttribute

• Main issue: #588771
• Parent epic: gitlab-org#18201

Query Plan

SELECT DISTINCT project_id
FROM project_to_security_attributes
WHERE (
    project_to_security_attributes.traversal_ids >= '{1}'
    AND '{2}' > project_to_security_attributes.traversal_ids
  )
  AND EXISTS (
    SELECT 1 FROM project_to_security_attributes exists_ptsa
    WHERE exists_ptsa.project_id = project_to_security_attributes.project_id
    AND exists_ptsa.security_attribute_id IN (1, 2)
  )
  AND NOT EXISTS (
    SELECT 1 FROM project_to_security_attributes not_exists_ptsa
    WHERE not_exists_ptsa.project_id = project_to_security_attributes.project_id
    AND not_exists_ptsa.security_attribute_id = 3
  );

See: https://console.postgres.ai/gitlab/gitlab-production-sec/sessions/49009/commands/146568

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Before	After

How to set up and validate locally

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