Assets external import to run as the generator of the OAuth token

Issue Summary

External import is running as unknown user

Steps to Reproduce

1. Create an external import configuration and generate the API token
2. Create the mapping via API
3. Execute the import

Expected Results

The import should run on the behalf of the user who generated the OAuth token or at least a bot account.

Actual Results

The import log shows that the actions were executed by "Unknown user" underneath the objects' history and "process results" tab.

Workaround

Currently there is no known workaround for this behaviour. A workaround will be added here when available

Notes:

This behaviour is seen when the imports are executed not via UI and hence is seen for external imports and also in cases where the import is kicked off externally via Discovery.