POL1-881: get counters for ies and vprn service interfaces

brian_polling_manager/interface_stats/vendors/nokia.py

test/interface_stats/conftest.py

test/interface_stats/data/capture-test-data-nokia.py

test/interface_stats/data/rt0.ams.nl.geant.net-iess.xml

test/interface_stats/data/rt0.ams.nl.geant.net-lags.xml

test/interface_stats/data/rt0.ams.nl.geant.net-ports.xml

...ace_stats/data/rt0.ams.nl.geant.net-router-interfaces.xml

test/interface_stats/data/rt0.ams.nl.geant.net-vprns.xml

...rface_stats/data/rt0.ams.nl.lab.office.geant.net-lags.xml

...face_stats/data/rt0.ams.nl.lab.office.geant.net-ports.xml

...ata/rt0.ams.nl.lab.office.geant.net-router-interfaces.xml

...rface_stats/data/rt0.lon.uk.lab.office.geant.net-lags.xml

...face_stats/data/rt0.lon.uk.lab.office.geant.net-ports.xml

test/interface_stats/data/rt0.lon2.uk.geant.net-iess.xml

test/interface_stats/data/rt0.lon2.uk.geant.net-lags.xml

test/interface_stats/data/rt0.lon2.uk.geant.net-ports.xml

...ce_stats/data/rt0.lon2.uk.geant.net-router-interfaces.xml

test/interface_stats/data/rt0.lon2.uk.geant.net-vprns.xml

test/interface_stats/test_interface_stats.py

test/interface_stats/test_nokia.py