Add warning event in audit logger

[ashutosh16]

Summary

Argo-cd loses the warning message when the user performs no-ops sync, which does not alter the resource state.
Since the kube-api server does not send a request to the OPA when the resource is not modified, the resource is synced without warning. In this case, it would be helpful to log this initial warning message in the audit log. The issue is logged as part of the improvement on this PR