DATACMNS-867 - Fixed glitch causing failure in PropertyDescriptor lookup for ProjectionInformation.

Re added PropertyDescriptor collection. Looks like the method got dropped during one of the rebase operations.
Additionally make use of .distinct() name collection in tests as descriptors might appear multiple times for the same property name.

src/test/java/org/springframework/data/projection/DefaultProjectionInformationUnitTests.java

@@ -60,6 +60,7 @@ public class DefaultProjectionInformationUnitTests {
 
 		return descriptors.stream()//
 				.map(FeatureDescriptor::getName)//
+				.distinct()
 				.collect(Collectors.toList());
 	}