Light Classes: Implement light elements for 'extends'/'implements' reference lists. Support adding/removing of super type list entries via light elements.

Fix exception on applying "Convert to class" intention to Java interface with Kotlin inheritor(s)
 #KT-11281 Fixed
(cherry picked from commit 4ec4914)

compiler/frontend/src/org/jetbrains/kotlin/psi/KtSuperTypeList.java

@@ -44,6 +44,11 @@ public class KtSuperTypeList extends KtElementImplStub<KotlinPlaceHolderStub<KtS
         return visitor.visitSuperTypeList(this, data);
     }
 
+    @NotNull
+    public KtSuperTypeListEntry addEntry(@NotNull KtSuperTypeListEntry entry) {
+        return EditCommaSeparatedListHelper.INSTANCE.addItem(this, getEntries(), entry);
+    }
+
     public void removeEntry(@NotNull KtSuperTypeListEntry entry) {
         EditCommaSeparatedListHelper.INSTANCE.removeItem(entry);
         if (getEntries().isEmpty()) {