title: ApiController is returning a double-escaped string for a CSV string
body: <p>I'm working on creating a CSV report in an asynchronous MQ framework. </p>
  
  <p>I have an endpoint set up that returns the CSV results accurately, i.e:</p>
  
  <p><code>Column 1, Column2, Column 3\r\nValue 1, Value 2, Value 3</code></p>
  
  <p>However, once this message is serialized and sent as a response, every result is double-escaped, i.e.</p>
  
  <p><code>\"Column 1, Column 2, Column 3\\r\\nValue 1, Value 2, Value 3\"</code></p>
  
  <p>... which makes the result parse with literal quotes and newline characters, which is obviously not a valid format for a CSV. </p>
  
  <p>I've tried <code>string.Trim('"')</code> and <code>Regex.Unescape()</code> on the return value before returning <code>ApiController.Ok(value)</code>, but it's the serialization in the <code>OK</code> method itself that's escaping the chars. I can't unescape them on the retrieving side, because the framework handles HTML and PDFs as well and has to be agnostic to the format of the returned string -- plus, this endpoint will be used in more places and should return an unescaped string.</p>
  
  <p>Any ideas on how to prevent this?</p>