Add Service Entries for SSO and external endpoints

Summary

SSO and grafana configurations, for example, were not accounted for in !145 (merged). We should add additional ServiceEntries to cover these use cases:

• SSO is enabled
• Grafana is deployed
• Tempo or Jaeger are deployed

Acceptance Criteria

• Egress to the services listed above is enabled when istio.hardened.enabled: true and those services are enabled