Fix several bugs in serialization of inner generic classes

- Interner was working incorrectly with parents
- nested classes were serialized in codegen out of any context

 #KT-5660 Fixed

compiler/testData/loadJava/compiledKotlin/nested/innerClassReferencesOuterTP.txt

@@ -0,0 +1,9 @@
+package test
+
+internal final class InnerClassReferencesOuterTP</*0*/ P> {
+    /*primary*/ public constructor InnerClassReferencesOuterTP</*0*/ P>()
+
+    internal final inner class Inner</*0*/ Q : P> {
+        /*primary*/ public constructor Inner</*0*/ Q : P>()
+    }
+}