[Fleet] Collect Fleet services that should be exposed as scoped services

[juliaElastic]

Collect list of all Fleet services that are used by other plugins. Fleet plans to refactor all of these services to include authorization check and expose as scoped services to other plugins.

Services we already know are required:

• AgentService
• PackageService
• PackagePolicyService
• AgentPolicyService

Goal of this task is to confirm we are aware of all services that have to be refactored.

• Issue raised for Osquery usage: https://github.com/elastic/kibana/issues/131240
• Issue raised for Security Endpoint usage: https://github.com/elastic/kibana/issues/132726
• Synthetics use case: https://github.com/elastic/uptime/issues/441

Related:

• Related Fleet RBAC work: https://github.com/elastic/obs-dc-team/issues/731
• change done for AgentService: https://github.com/elastic/kibana/pull/119017
• change done for PackageService: https://github.com/elastic/kibana/pull/121589
• draft for PackagePolicyService: https://github.com/elastic/kibana/pull/131233

cc @joshdover

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)