message: Fix result<T> constructors resolution during implicit conversions
  Convert existing value initializing constructor to templated one enabled
  for all types convertible to T.
diff: @@ -184,7 +184,9 @@ public:
  using super::super;
  - result(T x) : super(detail::result_base_message_init{}, std::move(x)) {
  + template <class U, class = std::enable_if_t<std::is_constructible_v<T, U>>>
  + result(U&& x)
  + : super(detail::result_base_message_init{}, T{std::forward<U>(x)}) {
  // nop
  }
  