Treat SEALED_SUBCLASS_FQ_NAME_LIST change as a class signature change

#KT-19580

jps-plugin/testData/comparison/classSignatureChange/sealedClassNestedImplAddedDeep/new.kt

@@ -0,0 +1,22 @@
+package test
+
+sealed class Base1 {
+    sealed class Nested1 : Base1() {
+        sealed class Nested2 : Nested1() {
+            class Nested3 : Nested2()
+        }
+    }
+}
+
+sealed class Base2 {
+    sealed class Nested1 : Base2() {
+        class Nested2 : Nested1()
+        class Nested3 : Nested1()
+    }
+}
+
+sealed class Base3 {
+    sealed class Nested1 : Base3() {
+        class Nested2 : Nested1()
+    }
+}

jps-plugin/testData/comparison/classSignatureChange/sealedClassNestedImplAddedDeep/old.kt

@@ -0,0 +1,19 @@
+package test
+
+sealed class Base1 {
+    sealed class Nested1 : Base1() {
+        sealed class Nested2 : Nested1()
+    }
+}
+
+sealed class Base2 {
+    sealed class Nested1 : Base2() {
+        class Nested2 : Nested1()
+    }
+}
+
+sealed class Base3 {
+    sealed class Nested1 : Base3() {
+        class Nested2
+    }
+}

jps-plugin/testData/comparison/classSignatureChange/sealedClassNestedImplAddedDeep/result.out

@@ -0,0 +1,12 @@
+ADDED test/Base1.Nested1.Nested2.Nested3
+ADDED test/Base2.Nested1.Nested3
+PROTO DIFFERENCE in test/Base1.Nested1.Nested2: NESTED_CLASS_NAME_LIST, SEALED_SUBCLASS_FQ_NAME_LIST
+CHANGES in test/Base1.Nested1.Nested2: CLASS_SIGNATURE, MEMBERS
+    [Nested3]
+PROTO DIFFERENCE in test/Base2.Nested1: NESTED_CLASS_NAME_LIST, SEALED_SUBCLASS_FQ_NAME_LIST
+CHANGES in test/Base2.Nested1: CLASS_SIGNATURE, MEMBERS
+    [Nested3]
+PROTO DIFFERENCE in test/Base3.Nested1: SEALED_SUBCLASS_FQ_NAME_LIST
+CHANGES in test/Base3.Nested1: CLASS_SIGNATURE
+PROTO DIFFERENCE in test/Base3.Nested1.Nested2: SUPERTYPE_LIST
+CHANGES in test/Base3.Nested1.Nested2: CLASS_SIGNATURE