[issue #2221] [issue #788] Lombok now adds nullity annotations.

Which 'flavour' is defined in lombok.config; applied to toString, equals, canEqual, and plural-form of `@Singular`.

test/transform/resource/before/NullLibrary2.java

@@ -0,0 +1,7 @@
+//CONF: lombok.addNullAnnotations = spring
+@lombok.EqualsAndHashCode
+@lombok.ToString
+@lombok.AllArgsConstructor
+public class NullLibrary2 {
+	@lombok.With String foo;
+}