test-selection gap: Extend detect-tests job to generate "GraphQL type class to related specs" mappings

Context

Part of Epic Broken Master Incident Remediation: Improve Test Selection Gap

In gitlab-org/quality/engineering-productivity/master-broken-incidents#476 (closed), we have noticed that if some GraphQL type are changed, and those types are GraphQL interfaces included in other GraphQL types, we should also run the specs for the GraphQL types including the interface.

Goal

If a GraphQL type class changed, we should try to identify the other GraphQL types that potentially include this type.