Add queuestat changes for aggregate VOQ counters

[vivekverma-arista]

What I did

Add queuestat changes for aggregate VOQ counters.

How I did it

Existing CLI show queue counters --voq is being implemented for supervisor. This will access all the ASIC database instances on every linecard which are now exposed to midplane network by this PR20803 and sum up counters for each VOQ.

Also depends on #560

How to verify it

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

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

[kenneth-arista]

@arlakshm for awareness

[kenneth-arista]

Tracking issue: sonic-net/SONiC#1543

[vmittal-msft]

@vivekverma-arista

1. Please share output from supervisor as well as line card using one port/voq as an example.
2. Do we have separate PR for clear counter ?
3. Did we check if queuestat still works for non chassis ?

[vmittal-msft]

Otherwise changes looks ok to me.

[vivekverma-arista]

@vivekverma-arista

1. Please share output from supervisor as well as line card using one port/voq as an example.
2. Do we have separate PR for clear counter ?
3. Did we check if queuestat still works for non chassis ?

Hi @vmittal-msft, I will answer/address these points. Meanwhile could you also take a look at another related PR sonic-net/sonic-buildimage#20803 and confirm that the approach is okay so that we can start making progress with unit tests.