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

js/js.translator/testData/classObject/cases/accessing.kt

@@ -3,7 +3,7 @@
 package foo
 
 class Foo() {
-    class object {
+    default object {
         val bar = "Foo.bar ";
         var boo = "FAIL";
         fun baz() = "Foo.baz() "

js/js.translator/testData/classObject/cases/inTrait.kt

@@ -1,7 +1,7 @@
 package foo
 
 trait A {
-    class object {
+    default object {
         val OK: String = "OK"
     }
 }

js/js.translator/testData/classObject/cases/namedClassObject.kt

@@ -1,13 +1,13 @@
 package foo
 
 trait Named {
-    class object Bar {
+    default object Bar {
         val g = "a";
     }
 }
 
 class Foo {
-    class object {
+    default object {
         val g = "b";
     }
 }

js/js.translator/testData/classObject/cases/setVar.kt

@@ -2,7 +2,7 @@ package foo
 
 class A {
     var a = 3
-    class object {
+    default object {
         var a = -2
     }
 }

js/js.translator/testData/classObject/cases/simple.kt

@@ -2,7 +2,7 @@ package foo
 
 class A {
     val a = 3
-    class object {
+    default object {
         val a = 2
         val b = 5
     }

js/js.translator/testData/classObject/cases/withInheritance.kt

@@ -5,13 +5,13 @@ open class A {
     fun foo(): Int {
         return 5
     }
-    class object: A() {
+    default object: A() {
         val c = a
     }
 }
 
 class B {
-    class object: A() {
+    default object: A() {
     }
 }