* api/allocations: GetTaskGroup finds the taskgroup struct
* command/node_status: display CSI volume names
* nomad/state/state_store: new CSIVolumesByNodeID
* nomad/state/iterator: new SliceIterator type implements memdb.ResultIterator
* nomad/csi_endpoint: deal with a slice of volumes
* nomad/state/state_store: CSIVolumesByNodeID return a SliceIterator
* nomad/structs/csi: CSIVolumeListRequest takes a NodeID
* nomad/csi_endpoint: use the return iterator
* command/agent/csi_endpoint: parse query params for CSIVolumes.List
* api/nodes: new CSIVolumes to list volumes by node
* command/node_status: use the new list endpoint to print volumes
* nomad/state/state_store: error messages consider the operator
* command/node_status: include the Provider
