A family restaurant thriving on Arthur Avenue in the Bronx one can understand. But in midtown? Yet the Scotto clan strolls around the dining room, cajoling, nudging, hugging, as if you’d shown up at their house for leftovers the day after Thanksgiving. Is it any wonder they have specific menus for Thanksgiving, Christmas Eve, Valentine’s Day, and Mother’s Day? For them, Fresco is one big welcome mat. Doesn’t matter that the pizza is to die for, the lasagna superb; and if you like liver, you may never want to leave.