Expected NoContentResult Throws ApiException due to null object

[kccarter76]

NoContentResult will always deserialize as a null and the template generation should return a new NoContentResult() when the status code is 204.

the following is a screen shot of what NSwag Studio is generating:

the following is the code that should be generated for this use case.

if you need the qualifying name space it is Microsoft.AspNetCore.Mvc