Have PipingCalculationRow only clear output when a value of a property has been actually changed. Extracted helper methods in PipingCalculationRowTest. Inlined resource in tests. Related to Issue [WTI-967] git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@7674 5a3db67b-de53-47b5-99c8-a1c30a6650e2