Format mac addresses in lldpadm output

[Nieuwejaar]

The MacAddress is currently being display as slice of base 10 numbers, which isn't all that ergonomic.

On interface qsfp0/0
        first seen:     1m54s ago
        last seen:        23s ago
        last changed:   1m54s ago
        ChassisID: MacAddress(MacAddr { a: [2, 66, 172, 32, 153, 108] })
        PortId: InterfaceName("Ethernet2")
        TTL:  120 seconds
        System Name: cr1
        System Description: Arista Networks EOS version 4.28.3M-28837868.4283M (engineering build) running on an Arista cEOSLab