Enhance description formatting

This translates | to non breaking spaces and still keeps these non breaking spaces
properly formatted.

This change is for https://www.pivotaltracker.com/story/show/46538537.

After deploy on EU002 footnote (https://www.gov.uk/trade-tariff/commodities/8108906020?country=&day=18&month=3&year=2013#import) and 06004 in https://www.gov.uk/trade-tariff/commodities/3907602000#import we should not be seeing html characters or wrong formatting.