Treat SEALED_SUBCLASS_FQ_NAME_LIST change as a class signature change

#KT-19580

jps-plugin/testData/comparison/classMembersOnlyChanged/nestedClassMembersChanged/new.kt

@@ -0,0 +1,9 @@
+package test
+
+class Base {
+    class Nested1 {
+        class Nested2 {
+            fun added() {}
+        }
+    }
+}

jps-plugin/testData/comparison/classMembersOnlyChanged/nestedClassMembersChanged/old.kt

@@ -0,0 +1,9 @@
+package test
+
+class Base {
+    class Nested1 {
+        class Nested2 {
+            fun removed() {}
+        }
+    }
+}

jps-plugin/testData/comparison/classMembersOnlyChanged/nestedClassMembersChanged/result.out

@@ -0,0 +1,3 @@
+PROTO DIFFERENCE in test/Base.Nested1.Nested2: FUNCTION_LIST
+CHANGES in test/Base.Nested1.Nested2: MEMBERS
+    [added, removed]