List host_nqns added to subsystem with subsystem list command

[rahullepakshi]

Proposing to list hostNQN's column along with 'Any Host' at subsystem list output to enhance usability. With namespace masking and subsystem host add , user will always benefit when host NQNs added to subsystem are displayed at subsystem list and hence compared with NQNs masked with namespace to eliminate confusion and invalid configuration when host visibility is set to both subsystem and namespace. WDYT?

[root@ceph-rlepaksh-8-1-065w2y-node3 ~]# podman run --rm quay.io/ceph/nvmeof-cli:latest --server-address 10.0.66.114 subsystem list
Subsystems:
╒═══════════╤═══════════════════════════════════╤════════════════════╤══════════════════╤═════════════╤══════════════╤════════════╤══════════╕
│ Subtype   │ NQN                               │ Serial             │ Controller IDs   │   Namespace │          Max │ Allow      │ DHCHAP   │
│           │                                   │ Number             │                  │       Count │   Namespaces │ Any Host   │ Key      │
╞═══════════╪═══════════════════════════════════╪════════════════════╪══════════════════╪═════════════╪══════════════╪════════════╪══════════╡
│ NVMe      │ nqn.2016-06.io.spdk:cnode1.group1 │ Ceph23571808504978 │ 1-2040           │           8 │         1400 │ Yes        │ No       │
├───────────┼───────────────────────────────────┼────────────────────┼──────────────────┼─────────────┼──────────────┼────────────┼──────────┤
│ NVMe      │ nqn.2016-06.io.spdk:cnode2.group1 │ Ceph67858855260085 │ 1-2040           │           8 │         1400 │ No         │ No       │
╘═══════════╧═══════════════════════════════════╧════════════════════╧══════════════════╧═════════════╧══════════════╧════════════╧══════════╛

[gbregman]

We have a "host list" command for that. We can't pack too much information on the subsystem list. It's already very packed.

[gbregman]

We can add a "show all" option to the subsystem list command. If this option is set the CLI will automatically execute all the commands needed to show the hosts and listeners for each subsystem. It's not feasible to have all the information in one table. What we can have is displaying the tables one after the other.