introduce inspect command

Introduce a command to scan baremetalhosts and retrieve their interfaces macs

It could be usefull when DHCP-less is used, as interface mac adresses (or names) have to be provided before the the initial inspection of the servers.

Here is the result of current implementation on Dell, HP and Lenovo servers:

$ ./sylvactl inspect bmhs/bm-workload-cluster.yaml 
===============================
Inspecting hpdl360-64
--- Inspecting ethernet interfaces ---
Interface: 13
        Description: 
        Address: 88:e9:a4:83:6f:ec
        LinkStatus: LinkUp
        SpeedMbps: 0
Interface: 141
        Description: 
        Address: 88:e9:a4:a9:28:f6
        LinkStatus: LinkUp
        SpeedMbps: 0
Interface: 14
        Description: 
        Address: 88:e9:a4:83:6f:ed
        LinkStatus: LinkUp
        SpeedMbps: 0
Interface: 142
        Description: 
        Address: 88:e9:a4:a9:28:f7
        LinkStatus: LinkUp
        SpeedMbps: 0
Interface: 5
        Description: 
        Address: 88:e9:a4:a8:34:c2
        LinkStatus: LinkUp
        SpeedMbps: 0
Interface: 6
        Description: 
        Address: 88:e9:a4:a8:34:c3
        LinkStatus: LinkUp
        SpeedMbps: 0
--- Inspecting disks ---
Drive 0
        Manufacturer: 
        Model: VK000480GZXRF
        Size: 447 GiB
        Serial number: S6MPNA0TB04686
        Part number: 
        Location: Bay 2
Drive 1
        Manufacturer: 
        Model: VK000480GZXRF
        Size: 447 GiB
        Serial number: S6MPNA0TB04675
        Part number: 
        Location: Bay 1
Drive 0
        Manufacturer: Samsung
        Model: VO003840KYDMV
        Size: 3576 GiB
        Serial number: S70LNE0TA08848
        Part number: 
        Location: Bay 2
Drive 0
        Manufacturer: Samsung
        Model: VO003840KYDMV
        Size: 3576 GiB
        Serial number: S70LNE0TA08846
        Part number: 
        Location: Bay 1
===============================
Inspecting lesr360-65
--- Inspecting ethernet interfaces ---
Interface: NIC2
        Description: External Ethernet Interface
        Address: B4:96:91:F6:94:FD
        LinkStatus: LinkUp
        SpeedMbps: 25000
Interface: ToManager
        Description: Host Network Interface
        Address: 3a:68:dd:9e:de:0b
        LinkStatus: LinkDown
        SpeedMbps: 0
Interface: NIC1
        Description: External Ethernet Interface
        Address: B4:96:91:F6:94:FC
        LinkStatus: LinkUp
        SpeedMbps: 25000
Interface: NIC3
        Description: External Ethernet Interface
        Address: B4:96:91:F6:95:04
        LinkStatus: LinkUp
        SpeedMbps: 25000
Interface: NIC4
        Description: External Ethernet Interface
        Address: B4:96:91:F6:95:05
        LinkStatus: LinkUp
        SpeedMbps: 25000
Interface: NIC5
        Description: External Ethernet Interface
        Address: EC:E7:A7:00:A9:E0
        LinkStatus: LinkUp
        SpeedMbps: 25000
Interface: NIC6
        Description: External Ethernet Interface
        Address: EC:E7:A7:00:A9:E1
        LinkStatus: LinkUp
        SpeedMbps: 25000
--- Inspecting disks ---
Drive 0
        Manufacturer: INTEL
        Model: INTEL SSDPF2KX038T1O
        Size: 3576 GiB
        Serial number: BTAX3186011B3P8CGN
        Part number: SSDPF2KX038T1O
        Location: Bay 9
Drive 1
        Manufacturer: INTEL
        Model: INTEL SSDPF2KX038T1O
        Size: 3576 GiB
        Serial number: BTAX318503303P8CGN
        Part number: SSDPF2KX038T1O
        Location: Bay 8
Drive 0
        Manufacturer: Samsung
        Model: MZ7L3480HCHQ-00A
        Size: 447 GiB
        Serial number: S6MFNE0T705408
        Part number: 
        Location: Bay 1
Drive 1
        Manufacturer: Samsung
        Model: MZ7L3480HCHQ-00A
        Size: 447 GiB
        Serial number: S6MFNE0T705411
        Part number: 
        Location: Bay 0

Closes: #70 (closed)