chore(test): add more debug element query helpers
chore(test): add more debug element query helpers

dmacfarlane/ng2-material,dmacfarlane/ng2-material,mailiam/ng2-material,Q-Free-OpenRoads/ng2-material,parmalatinter/ng2-material,dmacfarlane/ng2-material,parmalatinter/ng2-material,parmalatinter/ng2-material,Q-Free-OpenRoads/ng2-material,mailiam/ng2-material,Q-Free-OpenRoads/ng2-material,Q-Free-OpenRoads/ng2-material,mailiam/ng2-material,paulussup/ng2-material,paulussup/ng2-material,paulussup/ng2-material