Add field switch_port to object if_list

[arnoldnipper]

Currently an interface can only be pinned down to a switch via the switch_id. When trouble-shooting it would be good to know the exact location of the interface(s). A field if_descr could help. E.g.

"if_list": [
    {
        "switch_id": 10,
        "if_speed": 1000,
        "if_type": "1000BASE-LX",
        "if_descr": "chassis-1\/Gi1\/1\/14"
    }
]

[arnoldnipper]

Currently, an interface can only be pinned down to a switch via the switch_id. When trouble-shooting it would be good to know the exact location of the interface(s). A field switch_port could help. E.g.

"if_list": [
    {
        "switch_id": 10,
        "switch_port": "chassis-1\/Gi1\/1\/14",
        "if_speed": 1000,
        "if_type": "1000BASE-LX"
    }
]