The provisions of this article apply to all suits, actions and proceedings of whatever nature involving the validity of bonds of any locality or other political subdivision, agency or instrumentality of the Commonwealth or of any locality, whether the bonds are to be issued following an election on the question of their issuance or without necessity of an election. These provisions supersede all other acts and statutes on the subject and are controlling in all cases, notwithstanding the provisions of any other law or charter to the contrary.