fix(SW-2614): send language to API

We were missing the language param on some endpoints. We are still
missing it on some, but I left those without when we don't need it, e.g.
when only caring about the IDs in the response.

apps/scandic-web/components/HotelReservation/MyStay/ReferenceCard/Actions/NotCancelled/ManageStay/Actions/ChangeDates/Steps/Confirmation/index.tsx

@@ -89,6 +89,7 @@ export default function Confirmation({
       refId: bookedRoom.refId,
       checkInDate,
       checkOutDate,
+      language: lang,
     })
   }