[FIR2IR] Automatically store IR declaration in its parent upon creation

Previously, creating a declaration with Fir2IrCallableDeclarationsGenerator/
  Fir2IrClassifiersGenerator didn't guarantee that this declaration will
  be actually added to the list of parent class/file declarations, which
  lead to situations when FIR2IR created some declarations in the air
  (mostly fake-overrides)

compiler/testData/ir/irText/firProblems/substitutionOverrideWithDelegate.fir.kt.txt

@@ -22,6 +22,7 @@ open class DelegatedB : B<String> {
 
   }
 
+  private /* final field */ val $$delegate_0: C<String> = C<String>()
   override operator fun invoke() {
     <this>.#$$delegate_0.invoke()
   }
@@ -30,8 +31,6 @@ open class DelegatedB : B<String> {
     <this>.#$$delegate_0.invoke(value = value)
   }
 
-  private /* final field */ val $$delegate_0: C<String> = C<String>()
-
 }
 
 interface B<out T : Any?> : A {
@@ -46,3 +45,4 @@ class C<out T : Any?> : B<T> {
   }
 
 }
+