“Yesterday” is a charming bauble. Not a diamond. Perhaps a rhinestone — sparkling and attractive, yet unable to withstand any scratching of its surface.Like “Bohemian Rhapsody” and “Rocketman,” “Yesterday” offers nostalgic pleasure by reciting from the baby-boomer songbook.Jack Malik (Himesh Patel) is a struggling musician who has given up his teaching job to devote …