Enhancement:Link dampening feature test scripts commit

### Is it platform specific

generic

### Importance or Severity

Medium

### Description of the enhancement

This is a test scripts for the new feature link dampening mentioned in HLD: https://github.com/sonic-net/SONiC/pull/1071


### Current Behavior

This is a new feature and hence there is no scripts currently available

### Proposed Behavior

Added new test scripts to execute the test cases