Function sync_model_outputs_if_required 

pub fn sync_model_outputs_if_required(
    src: &TypedModel,
    node: &TypedNode,
    target: &mut TypedModel,
    target_node_outlet_ids: TVec<OutletId>,
) -> TractResult<TVec<OutletId>>

For model outputs that are on device, insert DeviceSync nodes to move them back to host.