Extended StochasticSoilModelCollection: - Class implements IObservable (to maintain similar functionality as the ObservableList) and IEnumerable (because it is still an iterable collection) - Class wraps a List with delegated methods indexer, Count, Add, Remove and Clear. AddRange was not implemented, because there was no reason to. - Added tests - Adjusted PipingFailureMechanismView, collection is not a derived class from the ObservableList anymore Related to Issue [WTI-1080] git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@7837 5a3db67b-de53-47b5-99c8-a1c30a6650e2