Feature/exception response (#663)

* return 500 code for other exception with json response

* not throw

src/PublicApi/Middleware/ExceptionMiddleware.cs

@@ -41,5 +41,12 @@ public class ExceptionMiddleware
                 Message = duplicationException.Message
             }.ToString());
         }
+
+        context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
+        await context.Response.WriteAsync(new ErrorDetails()
+        {
+            StatusCode = context.Response.StatusCode,
+            Message = exception.Message
+        }.ToString());
     }
 }