gnmi: Port previously reviewed changes over from main.go
gnmi: Port previously reviewed changes over from main.go

original review :- https://gerrit.corp.arista.io/c/goarista/+/207855
All review comments from previous change have ben ported.
File structure change forced this new change.
There was a question about interleaved responses from multiple subscribe points.
They are displayed with their path info.
nkarkhan@nkarkhan-OpenFlowPy3-0WithChanges-0:~/gnmi/gnmiCodeConflict/goarista/cmd/gnmi (master)

 130 > ./gnmi -addr upp202:6030 -username admin subscribe origin=eos_native "/Smash/interface/counter" origin=openconfig "lldp"
[2022-03-23T17:46:59.655247396Z] /Smash/interface/counter/name = counter
[2022-03-23T17:46:59.655286852Z] /Smash/interface/counter/lag/name = lag
[2022-03-23T17:46:59.65531111Z] /Smash/interface/counter/lag/current/name = current
[2022-03-23T17:46:59.655942403Z] /Smash/interface/counter/subintf/name = subintf
[2022-03-23T17:46:59.655969277Z] /Smash/interface/counter/subintf/current/name = current
[2022-03-23T17:46:59.657494834Z] /Smash/interface/counter/tunnel/name = tunnel
[2022-03-23T17:46:59.657523789Z] /Smash/interface/counter/tunnel/fastpath/name = fastpath
[2022-03-23T17:46:59.657549378Z] /Smash/interface/counter/tunnel/fastpath/current/name = current
[2022-03-23T17:47:06.257969504Z] /lldp/config/chassis-id = 44:4c:a8:7c:0b:cd
[2022-03-23T17:47:06.257969504Z] /lldp/config/chassis-id-type = MAC_ADDRESS
[2022-03-23T17:47:06.222320086Z] /lldp/config/enabled = false
[2022-03-23T17:47:06.222320086Z] /lldp/config/hello-timer = 30
[2022-03-23T17:47:06.222320086Z] /lldp/config/management-address/interface =
[2022-03-23T17:47:06.222320086Z] /lldp/config/management-address/network-instance = default
[2022-03-23T17:47:06.222320086Z] /lldp/config/management-address/transmit-mode = BEST
[2022-03-23T17:47:10.070526495Z] /lldp/config/suppress-tlv-advertisement = []
[2022-03-23T17:47:06.257969504Z] /lldp/config/system-description = Arista Networks EOS version 4.28.0F-26664256.vahabvanLL0eostrunk0 (engineering build) running on an Arista Networks DCS-7060CX2-32S
[2022-03-23T17:47:06.257969504Z] /lldp/config/system-name = upp202.sjc.aristanetworks.com
[2022-03-23T17:47:06.257969504Z] /lldp/state/chassis-id = 44:4c:a8:7c:0b:cd
[2022-03-23T17:47:06.257969504Z] /lldp/state/chassis-id-type = MAC_ADDRESS
[2022-03-23T17:47:06.222320086Z] /lldp/state/enabled = false
[2022-03-23T17:47:06.341676491Z] /lldp/state/hello-timer = 30
[2022-03-23T17:47:10.070533351Z] /lldp/state/suppress-tlv-advertisement = []
[2022-03-23T17:47:06.257969504Z] /lldp/state/system-description = Arista Networks EOS version 4.28.0F-26664256.vahabvanLL0eostrunk0 (engineering build) running on an Arista Networks DCS-7060CX2-32S
[2022-03-23T17:47:06.257969504Z] /lldp/state/system-name = upp202.sjc.aristanetworks.com

Change-Id: I85fa1b1c7b9f38ef33d7e72e9c35b37d3ac67d3e

aristanetworks/goarista,aristanetworks/goarista