Every action shall be prosecuted in the name of the real party in interest, but an executor, administrator, personal representative, guardian, conservator, trustee of an express trust, a party with whom or in whose name a contract has been made for the benefit of another, or a party authorized by statute may sue in his own name in such representative capacity without joining with him the party for whose benefit the action is brought; and when a statute so provides, an action for the use or benefit of another shall be brought in the name of the state of Missouri.