Made RequiredSafetyFactorStabilityInnerSlope, RequiredSafetyFactorStabilityOuterSlope, RequiredSafetyFactorPiping, UpliftCriterionStability and UpliftCriterionPiping required in xsd/DamLocation.xsd
Added DistanceToEntryPoint to Location (class and xsd), implemented it in the WtiPipingSellmeijerRevisedKernelWrapper. Added it to the Interface code (both FillDamFromXmlInput and FillXmlInputFromDam) with tests. Related to Issue [MWDAM-1361]