Add access control filtering of interface objects

Add access control filtering of interface objects

Ensure that all APIs which list interface objects filter
them against the access control system.

This makes the APIs for listing names and counting devices
slightly less efficient, since we can't use the direct
netcf APIs for these tasks. Instead we have to ask netcf
for the full list of objects & iterate over the list
filtering them out.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>