Currently the tenantId is included in the authenticatedUser object on the opCtx if it was provided as a part of the security token over the wire. This ticket is to create new object on the opCtx (different from the authenticatedUser object) that can store the tenantId in the event that it is passed some way other than the security token. This ticket should also set this new object when a tenantId is received in the $tenant field. Future work will need to be done to set this object when the tenantId is passed as a prefix or if some background thread is doing work on behalf of a tenant.