Deprecate setDatasetIdentifier from ExperienceEvent class

[addb]

Task description

• Deprecate the setDatasetIdentifier function in favor of setDatastreamConfigOverride feature.
• Discuss and decide changes for XDMSchema class which takes in datasetIdentifier.

Additional implementation details or code snippet(s)

No response

[emdobrin]

This change will also require wrapper updates, we'll put this on hold for now.