Structural studies on metal complexes of chiral cyclen. V. Chloro[(2RS,5RS,8RS,11SR)-1,4,7,10-tetrabenzyl-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane]copper(II) dichlorocuprate(I) ethanol solvate, [CuCl(C44H60N4)][CuCl2].3C2H6O