[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/FakeOverrideInAnonymousWithDelegation.fir.kt.txt

@@ -29,13 +29,12 @@ class Wrapper {
 
         }
 
+        private /* final field */ val $$delegate_0: <no name provided> = <this>.<get-dummy>()
         override val foo: String
           override get(): String {
             return <this>.#$$delegate_0.<get-foo>()
           }
 
-        private /* final field */ val $$delegate_0: <no name provided> = <this>.<get-dummy>()
-
       }
 
       <no name provided>()
@@ -51,3 +50,4 @@ interface Bar {
     }
 
 }
+