[FIR] Make type parameters inaccessible for non-inner nested types

#KT-57209

compiler/testData/diagnostics/tests/inner/outerGenericParam.fir.kt

@@ -1,6 +1,6 @@
 class Outer<T> {
     class Nested {
-        fun foo(t: T) = t
+        fun foo(t: <!UNRESOLVED_REFERENCE!>T<!>) = t
     }
     
     class Nested2<T> {
@@ -10,4 +10,4 @@ class Outer<T> {
     inner class Inner {
         fun foo(t: T) = t
     }
-}
+}