Init transfer clients with prometheus_metrics

[davramov]

Grafana is now running on flow-prd (flow-prd.als.lbl.gov/grafana), and works with the test flow. However, we need to update the transfer controller initialization in the alcf/nersc reconstruction flows to monitor transfer rates. Right now, they are initialized without prometheus_metrics=prometheus_metrics, so the metadata is not captured. It should be a simple thing to implement.

    transfer_controller = get_transfer_controller(
        transfer_type=CopyMethod.GLOBUS,
        config=config,
        prometheus_metrics=prometheus_metrics
    )