Oxidation of Metal-meso-Octaethylporphyrinogen Complexes Leading to Novel Oxidized Forms of Porphyrinogen Other than Porphyrins. 1. The Redox Chemistry of Nickel(II)- and Copper(II)-meso-Octaethylporphyrinogen Complexes Occurring with the Formation and Cleavage of a Cyclopropane Unit