[Saved Objects] Add ability to know when a onCopy happens vs onExport

[FrankHassanabad]

Parent Meta: #109169

Describe the feature:
In the existing implementation, the Kibana core onExport is called for both copying and for exporting saved objects. The export option for rules already removes particular fields such as apiKey, apiKeyOwner, scheduledTaskId. Export also sets the value of enabled to be false.

However, on copying a rule and its references, we will need to re-provision the apiKey, apiKeyOwner and then update other fields such as updated_at, updated_by as well as do deep copying of exception lists so that the list_id and any other fields are not shallow linked between each other.

Describe a specific use case for the feature:
As a platform engineer, when I export vs. when I do a copy I need the Saved Object (SO) types of rules, exception lists, etc... to behave in two different ways.

The export functionality should preserve common fields such as updated_by, updated_at, etc...
The copying functionality should update these values to new values of last updated, who last updated it, etc.... The created_at, created_by should change to the author of who is copying it unless other examples show something different.

[elasticmachine]

Pinging @elastic/security-detections-response (Team:Detections and Resp)

[elasticmachine]

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

[pgayvallet]

As discussed, adding a purpose option to the exporter's exportByTypes and exportByObjects APIs, and then re-expose them it in the export context provided to the type owners via SavedObjectsExportTransformContext