If no such action or proceedings are commenced or instituted within twenty days after the first publication of such resolution, other proceedings or notice, then all residents and taxpayers and owners of property in the authority and all public bodies and all other persons whatsoever shall be forever barred and foreclosed from instituting or commencing any action or proceeding in any court or from pleading any defense to any action or proceedings questioning the validity of the creation and establishment of the authority, the validity or proper authorization of such securities or the validity of any such covenants, agreements or contracts. The securities, covenants, agreements and contracts shall be conclusively deemed to be valid and binding obligations in accordance with their terms and tenor.