Copper(II) Coordination Compounds with Bis(imidazol-2-yl)methylamine and Bis(imidazol-2-yl)methylaminomethane in Relation to Bis(imidazol-2-yl)methylamine-Modified Poly(glycidyl methacrylate) Polymers and Other Bis(imidazol-2-yl)-Containing Ligands