The milkshakes coming out of the kitchen at Beyond Sweet(5901 Delmar Boulevard, 314-899-5021), the new ice cream shop just east of the Delmar Loop, have to be seen to be believed. They are dipped in chocolate and coated in marshmallow, studded with sprinkles and piled high with whipped cream.And that doesn't even mention the garnishes, which are seriously otherworldly.…