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

compiler/testData/loadJava/compiledKotlin/fromLoadJava/classObjectAnnotation.kt

@@ -1,7 +1,7 @@
 package test
 
 class Some {
-  TestAnnotation class object {
+  TestAnnotation default object {
     annotation class TestAnnotation
   }
 }