Crystal Structure, Spectral, Electronic, NLO Studies, and Bioactivity of 3′-(1-Benzyl-5-Methyl-1H-1,2,3-Triazole-4-Carbonyl)-4′-(4-Bromophenyl)-1′-Methyl-2H-Spiro [Acenaphthylene-1,2′-Pyrrolidine]-2-One