Handled SavedObjectsClient errors logged at the error level

[kobelb]

The new ES Client automatically logs all errors at the error log level, even if the errors are appropriately handled by the calling code. This is the root-cause of log messages similar to the following showing up during Kibana's start-up:

log [08:18:53.459] [error][data][elasticsearch] [version_conflict_engine_exception]: [task:Lens-lens_telemetry]: version conflict, document already exists (current version [4])

The legacy ES Client did not log these version_conflict_engine_exception errors at the error level.

This behavior with the new ES Client can be suppressed by ignoring specific error codes, but this is not done automatically by the SavedObjectsClient, and there is no way to opt-in to this behavior.

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)

[kobelb]

Closing as dupe of #84447... Should've searched first.