Implement hydraulic boundary locations sorted by distance in drop down menu: - Adjusted IHasHydraulicBoundaryLocationProperty interface to include and return SelectableHydraulicBoundaryLocation - Implemented SelectableHydraulicBoundaryLocation for all context classes when applicable - Adjusted and extended tests Related to Issue [WTI-989] git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@6821 5a3db67b-de53-47b5-99c8-a1c30a6650e2