Synthesis and Structural Characterization of the Co(III) Complex with 2'-[1-(2-Pyridinyl)-Ethylidene]-Oxamohydrazide (Hapsox): The Crystal Structure of Bis-{2'-[1-(2-Pyridinyl)-Ethylidene]-Oxamohydrazido} Cobalt(III) Perchlorate, [Co(apsox)2]ClO4