title: Convert unicode symbols \uXXXX in String to Character in Swift
body: <p>I'm receiving via a REST API a string which contains unicode encoded characters in form of <code>\uXXXX</code></p>
  <p>e.g. <code>Ain\u2019t</code> which should be <code>Ain’t</code></p>
  <p>Is there a nice way to convert these?</p>