Fix measurement unit qualifier display

Measurement unit qualifier is now included in duty expression.

This change is for https://www.pivotaltracker.com/story/show/46443953.

After deploy we expect Third country duty in the following commodity (https://www.gov.uk/trade-tariff/commodities/1702201000?country=&day=19&month=3&year=2013#import) to have the following duty expression: "0.40 EUR / (Hectokilogram/Per 1% by weight of sucrose)".

EU Taric uses abbreviations, we display full description for now.