Enhancement: Stop packet captures by VM interface

[eric-c-wood]

It is desired to extend the capture cli to stop a packet capture by specifying both the VM name and interface index. Currently, all packet captures are stopped for the VM via the command capture <pcap,> <delete,> vm <vm name> Since we are able to start a packet capture for a specific VM interface, it makes sense to be able to stop a packet capture for a specific interface.

I wrote dependent code that starts packet captures based on a subnet. It would be nice to continue to rely on the capture cli to stop packet captures by subnet. Currently, if a VM has an interface in a specific subnet, all packet captures for the VM are stopped using the capture cli.