Add notify_fault to vrrp_instance configuration

I’ve noticed that a useful feature for vrrp is not in the configuration for vrrp notify_fault
there are configuration nodes for notify_master and notify_backup, but if the interface goes into a fault state there’s no notify_fault.

Can this be added to a rolling release?

@ACiD_GRiM this exist in CLI

vyos@R2# set high-availability vrrp group group1 transition-script 
Possible completions:
   backup       Script to run on VRRP state transition to backup
   fault        Script to run on VRRP state transition to fault
   master       Script to run on VRRP state transition to master

Also exist related task on phabricator with adding notify_stop https://phabricator.vyos.net/T1884