improved footer nav links for mobile, some refactoring
improved footer nav links for mobile, some refactoring


Former-commit-id: 168149c60e4638610331305f5ebba2a3f8e72dfd
dvla/vrm-retention-online,dvla/vehicles-online,dvla/vehicles-presentation-common,dvla/vehicles-online,dvla/vrm-retention-online,dvla/vehicles-online,dvla/vrm-retention-online,dvla/vrm-retention-online,dvla/vehicles-presentation-common,dvla/vehicles-online,dvla/vehicles-presentation-common