add MAC, IPv4, IPv6 addresses to nework inspect

[coderbirju]

Current network inspect respone provides only container names
This PR adds other fields in the EndpointResource Struct

Testing:

CIDR Notation:

$ sudo nerdctl network create test-net --subnet 10.88.0.0/16
$ sudo nerdctl run -d --name test-container --network test-net nginx:alpine
$ sudo nerdctl network inspect test-net | jq -r '.[].Containers'

Result

{
  "70aaec372b1f...": {
    "Name": "test-container",
    "MacAddress": "fe:5d:85:64:d2:96",
    "IPv4Address": "10.88.0.2/16", 
    "IPv6Address": ""
  }
}

Multi-Network Container:

$ sudo nerdctl network create hoge --subnet 10.91.0.0/16
$ sudo nerdctl network create fuga --subnet 10.92.0.0/16
$ sudo nerdctl run -d --name test2 --network hoge --network fuga nginx:alpine

-hoge

$ sudo nerdctl network inspect hoge | jq -r '.[].Containers'

{
  "0d7e17a42d25...": {
    "Name": "test2",
    "MacAddress": "ca:ad:6d:42:7a:03",  ← Unique to hoge
    "IPv4Address": "10.91.0.3/16",      ← From hoge subnet
    "IPv6Address": ""
  }
}

-fuga

$ sudo nerdctl network inspect fuga | jq -r '.[].Containers'


{
  "0d7e17a42d25...": {
    "Name": "test2",
    "MacAddress": "ca:f2:87:2c:4e:df",  ← Different MAC
    "IPv4Address": "10.92.0.2/16",      ← Different IP from fuga subnet
    "IPv6Address": ""
  }
}

[coderbirju]

Apologies for the late reply, you're right we can skip the assert statements as the field existence is already validated through struct unmarshaling.

@haytok

[haytok]

There are no tests for the items added in this PR's changes. Should add assertions for IPv4Address, MacAddress, and IPv6Address.