(Reuters) - British retailer WH Smith on Thursday said total revenues plunged 85% in April as sales at its airport and train station shops and kiosks were hit by government travel restrictions to halt the spread of the coronavirus.WH Smith, founded more than 200 years ago as a news vendor in London, has expanded at a host of major airports to take advantage of rising passenger numbers to help to offset the decline of British high street shopping. The company, which now sells everything from..