By ANNE D'INNOCENZIO, AP Retail Writer NEW YORK (AP) — Shares of The RealReal jumped on their first day of trading Friday, as the secondhand-fashion online retailer tests investors' appetite for the staying power of online marketplaces for pre-owned discounted Gucci and other luxury goods. The San Francisco company, founded in 2011 by CEO Julie Wainwright, debuted on the Nasdaq Stock Market and is