Fix for PTM cable status change notification not being handeled in Zebra

Fix for PTM cable status change notification not being handeled in Zebra

Ticket: CM-6690
Reviewed By: Donald, Kanna
Testing Done:

Double commit of 4bbc0cf4a98d7fd2aabe47241424fa7c5a3ae1eb from br2.5 to master

PTM cable status updates were not being handled in the notification callback registered with the ptm lib. This results in interface ptm status mismatch between PTM and zebra when interface cable check status changes (pass->fail or fail->pass). Zebra requests PTM to send cable status updates using get-status command and PTM sends the cable status updates as command responses to get-status. This was being handled in the commmand response callback registered with ptm lib. But, the subsequent status updates come as notifications and handling of those notifications that was missing in the notification callback. Fixed the issue by making a common callback for command responses and notifications. All the command responses other than the responses to get-status are dropped/ignored.