CHICAGO — Frank Galati, a pivotal figure over five decades in Chicago theater, a Tony Award-winning Broadway director, a beloved longtime teacher at Northwestern University, an ensemble member at both the Steppenwolf and Goodman theaters and a pioneer in the adaptation of novels and other narrative sources into exciting drama, died Monday night at 79 years old. His death was announced by his husband Peter Amster. Galati had retired to Florida with Amster, but he had hardly paused a career that argued he was perhaps the most influential Chicago theater artist the city has ever seen. And, as it …