The Swiss franc appreciated vis-à-vis the U.S. dollar today as the greenback tested bids around the CHF 1.0540 level and was capped around the CHF 1.0600 figure.   Data to be released in Switzerland this week include the March producer and import price index. Last Friday, Swiss National Bank Governing Board member Danthine said avoiding inflation is a medium-term challenge.  U.S. dollar offers are cited around the CHF 1.0920 level.  The euro moved lower vis-à-vis the Swiss franc as the single currency tested bids around the CHF 1.4335 level while the British pound moved lower vis-à-vis the Swiss franc and tested bids around the CHF 1.6215 level.