Added ConfirmingVariationCoefficientDistributionPropertiesBase. Added ConfirmingVariationCoefficientLogNormalDistributionProperties. Implemented inquiry of user for StructuresInputBaseProperties Related to Issue [WTI-1128] git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@8374 5a3db67b-de53-47b5-99c8-a1c30a6650e2