A chair and a guitar. A table holding an old-fashioned radio. A vase full of purple flowers. A teacup and saucer. Was this a scene from an oft-told tale or real life? At Best Video on Saturday, it was the setting for“Stories: An Evening with Shandy Lawson,” in which the New Haven-based singer-songwriter shared a collection of songs that offered a bit of fiction, a bite of truth, and a tasty twist on each.