Add illustratiepunteninlezen xml elements to calculation configuration importer and exporter Related to Issue [WTI-1385]git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@11970 5a3db67b-de53-47b5-99c8-a1c30a6650e2Former-commit-id: 7176d3b20eae80e886690b597a4e49b523821e3aFormer-commit-id: 244f15b869ac0a797fb2fc3f1e05d94ee2db449b