Thermodynamic Stability and Physicochemical Characterization of Ligand (4S)-4-Benzyl-3,6,10-tris(carboxymethyl)-3,6,10-triazadodecanedioic Acid (H~5[(S)-4-Bz-ttda]) and Its Complexes Formed with Lanthanides, Calcium(II), Zinc(II), and Copper(II) Ions