[wcmp]: Add WCMP CLI

[nazariig]

Signed-off-by: Nazarii Hnydyn [email protected]

HLD: https://github.com/sonic-net/SONiC/pull/1629

What I did

• Implemented CLI for Weighted-Cost Multi-Path feature

How I did it

• Integrated Weighted-Cost Multi-Path interface into config and show CLI root

How to verify it

1. Run Weighted-Cost Multi-Path CLI UTs

Previous command output (if the output of a command-line utility has changed)

• N/A

New command output (if the output of a command-line utility has changed)

admin@sonic:/home/admin# show bgp device-global
TSA      WCMP
-------  -------
enabled  enabled
admin@sonic:/home/admin# show bgp device-global --json
{
    "tsa": "enabled",
    "wcmp": "enabled"
}