Separated progress steps: - Validation or processing imported data is extracted out of the "Adding data to Model" step. Separate progress message added and made it cancellable - Added test to verify behaviour Related to Issue [WTI-1192] git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@8680 5a3db67b-de53-47b5-99c8-a1c30a6650e2