Bob Moyer takes a slight diversion into history and an entertaining novel based on the true story of a woman crime fighter. Reviewed by Robert P. Moyer MISS KOPP’S MIDNIGHT CONFESSIONS. By Amy Stewart. Houghton Mifflin Harcourt. 384 pages. $26. Don’t judge this book by its cover. Although the titillating title suggests some salacious material inside, there is…