Replace 'class object' with 'default object' in renderers and test data

Includes changes to decompiled text
Old syntax is used in builtins and project code for now

idea/testData/javaFacade/classObject.kt

@@ -1,7 +1,7 @@
 package foo
 
 class TheClass() {
-    class object {
+    default object {
         val out = System.out
     }
 }

idea/testData/javaFacade/classWithObjectLiteralInClassObjectField.kt

@@ -3,7 +3,7 @@ package test
 trait A
 
 class <caret>B {
-    class object {
+    default object {
         fun bar() = object : A { }
     }
 }

idea/testData/javaFacade/wrapFunInClassObject.kt

@@ -1,5 +1,5 @@
 class Test {
-  class object {
+  default object {
     fun <caret>testing() {
     }
   }