Enhancement: Add sonic-mgmt tests for "VoQ aggregate counter" feature

### Is it platform specific

generic

### Importance or Severity

Medium

### Description of the enhancement

This is an enhancement request to add sonic-mgmt tests for "VoQ aggregate counter"  fetaure.

### Current Behavior

new feature

### Proposed Behavior

https://github.com/sonic-net/SONiC/pull/1957