Dropping package facades:

- light classes: do not generate light class for package facade
- drop package facades as multifile classes compilation mode support
- get rid of some additional package facade fqName usages
- update tests for light classes

idea/testData/inspections/unusedSymbol/property/usedInJava.java

@@ -5,8 +5,8 @@ import foo.Obj;
 
 class usedInJava {
     public static void main(String[] args) {
-        FooPackage.getUsedByGetter();
-        FooPackage.setUsedBySetter(":|");
+        UsedInJavaKt.getUsedByGetter();
+        UsedInJavaKt.setUsedBySetter(":|");
         System.out.println(Obj.CONST);
     }
 }