vrf: T4562: Rewrite show vrf name xxx delete old script op-mode

[sever-sever]

Change Summary

Add option --name for function show to get the required VRF name
Delete old script show_vrf.py

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://phabricator.vyos.net/T4562

Component(s) name

vrf

Proposed changes

How to test

VyOS config:

vyos@r14:~$ show conf com | match vrf
set interfaces ethernet eth1 vif 2 vrf 'foo'
set interfaces ethernet eth1 vif 5 vrf 'bar'
set vrf name bar table '1020'
set vrf name foo table '1010'
vyos@r14:~$ 

Show specific VRF:

vyos@r14:~$ show vrf foo
Name    State    MAC address        Flags                     Interfaces
------  -------  -----------------  ------------------------  ------------
foo     up       aa:de:40:58:2e:dd  noarp,master,up,lower_up  eth1.2
vyos@r14:~$ 

Get raw data:

vyos@r14:~$ /usr/libexec/vyos/op_mode/vrf.py show --name bar --raw
[
    {
        "ifname": "bar",
        "operstate": "UP",
        "address": "ce:c1:4f:e8:dc:9a",
        "flags": [
            "NOARP",
            "MASTER",
            "UP",
            "LOWER_UP"
        ]
    }
]
vyos@r14:~$

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly