[Lombok K1] Support @Singular annotation

^KT-46959

plugins/lombok/testData/diagnostics/builderSingularNullability.kt

@@ -0,0 +1,50 @@
+// FIR_IDENTICAL
+// WITH_STDLIB
+// FULL_JDK
+// FILE: User.java
+import lombok.Builder;
+import lombok.Data;
+import lombok.Singular;
+
+@Builder
+@Data
+public class User {
+    @Singular private java.util.List<String> names;
+}
+
+// FILE: UserWithoutNull.java
+import lombok.Builder;
+import lombok.Data;
+import lombok.Singular;
+
+@Builder
+@Data
+public class UserWithoutNull {
+    @Singular(ignoreNullCollections = false) private java.util.List<String> names;
+}
+
+// FILE: UserWithNull.java
+import lombok.Builder;
+import lombok.Data;
+import lombok.Singular;
+
+@Builder
+@Data
+public class UserWithNull {
+    @Singular(ignoreNullCollections = true) private java.util.List<String> names;
+}
+
+// FILE: test.kt
+fun test() {
+    User.builder()
+        .name("User")
+        .name(<!NULL_FOR_NONNULL_TYPE!>null<!>) // error
+
+    UserWithoutNull.builder()
+        .name("User")
+        .name(<!NULL_FOR_NONNULL_TYPE!>null<!>) // error
+
+    UserWithNull.builder()
+        .name("User")
+        .name(null) // ok
+}