Fix Quagga ptm status per interface to show more meaningful status

 Fix Quagga ptm status per interface to show more meaningful status

Ticket: CM-6812
Reviewed By: Donald
Testing Done:

Double commit of 2119c8fccda5f1497820009c6f1f82eda3c8d0f1 from 2.5br to master

 In Quagga, the ptm status is shown as pass for all the interfaces that PTM is not tracking. When ptm is enabled in Quagga all the interfaces are initialized as pass and changed to fail/pass when ptm cable check updates are received. For all the interfaces for which no status was received from PTM remain at pass status. Interface show in quagga indicates wrong status and it should be n/a for all the untracked interfaces. To fix the problem introduced a third state “unknown” and this is default ptm status for all the interfaces. The ptm status is updated accordingly to pass/fail when the updates are received from PTM. Also, reset all interface ptm status to unknown when the connection with ptm is lost and the status gets updated when the connection with PTM is re-established.