for_in_of_invalid_element_type should differenciate type declaration

[FMorschel]

Repro

a.dart

class A {}
List<A> foo() => [A()];

main.dart

import 'a.dart';

class A {}

void main() {
  for (A a in foo()) {
  }
}

Shows:

The type 'List<A>' used in the 'for' loop must implement 'Iterable' with a type argument that can be assigned to 'A'.

Similar to #56505.