network-get format yaml keys differ from format json

I've found while investigating lp#1897261 that there's a different key path for address data between yaml and json outputs of network-get.

Note the path in json to 10.0.8.140 is: data[bind-addresses][0][addresses][0][value]
But the path in yaml to the same element is: data[bind-addresses][0][addresses][0][address]

Since charmhelpers uses the yaml format for network_get abstraction, charms should use the second path with key name "address", but anyone wanting to parse the json will find they need to use the "value" key name.

ubuntu@juju-22b3c3-0:~$ sudo juju-run designate/0 "network-get juju-info --format json"|jq .
{
  "bind-addresses": [
    {
      "mac-address": "00:16:3e:7e:85:b6",
      "interface-name": "eth0",
      "addresses": [
        {
          "hostname": "",
          "value": "10.0.8.140",
          "cidr": "10.0.8.0/24"
        }
      ]
    }
  ],
  "egress-subnets": [
    "10.0.8.140/32"
  ],
  "ingress-addresses": [
    "10.0.8.140"
  ]
}
ubuntu@juju-22b3c3-0:~$ sudo juju-run designate/0 "network-get juju-info --format yaml"
bind-addresses:
- macaddress: 00:16:3e:7e:85:b6
  interfacename: eth0
  addresses:
  - hostname: ""
    address: 10.0.8.140
    cidr: 10.0.8.0/24
egress-subnets:
- 10.0.8.140/32
ingress-addresses:
- 10.0.8.140