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.kt

@@ -0,0 +1,5 @@
+package test
+
+class InnerClassReferencesOuterTP<P> {
+    inner class Inner<Q : P>
+}