SAN DIEGO — William Fentress was just a teenager when he sailed off to Midway as a Navy cook. At a private screening Thursday for the movie based on the battle he saw with his own eyes — we’ll get to how bad the movie was in a second — the 94-year-old quietly recounted his experience aboard the USS Yorktown (CV-5) and the months leading up to that pivotal engagement. “We got to Hawaii after the Ba