As temperatures hover below freezing in Chicago, dozens of asylum-seekers are staying in the lower level of a library until the bitter cold gripping much of the country lifts.But after that, Chicago’s plans for offering immediate shelter to the growing number of migrants arriving in the nation’s third-largest city remain murky.For more than a year, Chicago has wrestled with how to house new arrivals until shelter space is free, utilizing measures that city leaders insist are a stopgap. Last week, it was parked city buses …