Use core security APIs in Observability solution plugins

[smith]

We've received a notification from the Kibana team:

The following platform security APIs are now accessible via Core services (and also exposed via Core's request handler context):

• authentication: core.security.authc
• user profile: core.userProfile
• audit logging: core.security.auditLogging

In general, for all teams having a direct dependency on the security plugin and utilizing those moved/deprecated APIs, we would kindly ask them to open an issue about switching to the Core APIs, and prioritizing the work so that the transition is made before the date those APIs are planned for to removed at (so ideally before EOY 2024).

If you have any questions, feel free to reach out to us on the #kibana-core channel.

We're using core.security.authc in the APM, Synthetics, and AI assistant plugins.

See #174578

✅ Acceptance criteria

• None of the observability solution plugins depend on the security plugin.
• Uses of the security APIs are replaced with their counterparts from core.

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)