Changed storage so that it handles with BackgroundData instead of BackgroundMapDataContainer. Related to Issue [WTI-1141]git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@8674 5a3db67b-de53-47b5-99c8-a1c30a6650e2Former-commit-id: 652d7c5d33baf5b6bd70ed7a4cccecaaceebb70cFormer-commit-id: 96597a4870ef0ed6b2e8d8e9a2f420882e740f67