Migration to actual/expect: quick-fix CreateActualFix with tests

idea/testData/multiModuleQuickFix/sealed/header/header.kt

@@ -1,4 +1,4 @@
-// "Create header class implementation for platform JS" "true"
+// "Create actual class for platform JS" "true"
 
 header sealed class <caret>Sealed {
     object Obj : Sealed

idea/testData/multiModuleQuickFix/sealed/header/header.kt.after

@@ -1,4 +1,4 @@
-// "Create header class implementation for platform JS" "true"
+// "Create actual class for platform JS" "true"
 
 header sealed class Sealed {
     object Obj : Sealed

idea/testData/multiModuleQuickFix/sealed/js/Sealed.kt.after

@@ -1,5 +1,5 @@
 // Sealed: to be implemented
-impl sealed class Sealed {
+actual sealed class Sealed {
     object Obj : Sealed
 
     class Klass(x: Int) : Sealed