[Filebeat] Okta Entity Analytics - Enrich users with group info

[andrewkroh]

Describe the enhancement:

Add group membership information to the user objects that are reported by the Okta provider within the Entity Analytics input. This would be similar to how the Entra ID provider reports groups with users.

https://developer.okta.com/docs/reference/api/users/#request-parameters-8

Describe a specific use case for the enhancement or feature:

The group membership information can be used for auditing purposes. By analyzing group membership changes, you can identify potential security incidents, such as insider attacks or privilege escalation.

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)