This is so the frontend will be able to display the organization name in the audit log row.

I addedMinimalOrganization to mirrorMinimalUser. It will be omitted if there was no organization, which I felt made more sense in the frontend (rather than the uuid zero value), but I can change that back if we want.

This new object replaces the old organization ID property on audit logs. Technically a breaking change? But we were not using it and I doubt anyone else was.

This is explained in the commit message, butparams.OrganizationID == uuid.Nil was removed from the test audit log creation so I could test audit logs without an org.

Part 1 of#13913