Provide a gRPC/CLI command to get the ana optimized states per subsystem on a specific gw

[caroav]

For example:

./usr/libexec/spdk/scripts/rpc.py nvmf_subsystem_get_listeners nqn.2016-06.io.spdk:cnode1.mygroup1

Will return something like:
{
"address": {
"trtype": "TCP",
"adrfam": "IPv4",
"traddr": "10.243.64.12",
"trsvcid": "4420"
},
"ana_states": [
{
"ana_group": 1,
"ana_state": "optimized"
},
{
"ana_group": 2,
"ana_state": "inaccessible"
},
{
"ana_group": 3,
"ana_state": "inaccessible"
},
{
"ana_group": 4,
"ana_state": "inaccessible"
},
{
"ana_group": 5,
...

We need to see the list of ana group ids that are defined as optimized. The command should be something like:

cli subsystem list optimized

[gbregman]

@caroav we already have a "listener list" command. We can just add this information to its output.

[caroav]

Its not the same. The listeners is a static configuration. The ana states are dynamic and per spdk (per gw).

[gbregman]

We agreed to add this information to the existing "listener list" command. When the listener belongs to a different gateway and the ANA information is not available we'll just put "<n/a>" instead. This information will only be added when the user pass a special flag in the command line so it won't change the output in a regular use.