Removed NioTSO client and server

- NioTSO client isn't needed because we're using RayLib
- Added FreeSO's API server to handle most backend operations

server/FSO.Server.Api.Core/Utils/ApiResponse.cs

@@ -0,0 +1,78 @@
+using FSO.Common.Utils;
+using FSO.Server.Database.DA.Utils;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using System;
+using System.Net;
+using System.Xml;
+
+namespace FSO.Server.Api.Core.Utils
+{
+    public class ApiResponse
+    {
+        public static IActionResult Plain(HttpStatusCode code, string text)
+        {
+            return new ContentResult
+            {
+                StatusCode = (int)code,
+                Content = text,
+                ContentType = "text/plain"
+            };
+        }
+
+        public static IActionResult Json(HttpStatusCode code, object obj)
+        {
+            return new ContentResult
+            {
+                StatusCode = (int)code,
+                Content = Newtonsoft.Json.JsonConvert.SerializeObject(obj),
+                ContentType = "application/json"
+            };
+        }
+
+        public static IActionResult PagedList<T>(HttpRequest request, HttpStatusCode code, PagedList<T> list)
+        {
+            request.HttpContext.Response.Headers.Add("X-Total-Count", list.Total.ToString());
+            request.HttpContext.Response.Headers.Add("X-Offset", list.Offset.ToString());
+
+            return new ContentResult
+            {
+                StatusCode = (int)code,
+                Content = Newtonsoft.Json.JsonConvert.SerializeObject(list),
+                ContentType = "application/json"
+            };
+        }
+
+        public static IActionResult Xml(HttpStatusCode code, IXMLEntity xml)
+        {
+            var doc = new XmlDocument();
+            var firstChild = xml.Serialize(doc);
+            doc.AppendChild(firstChild);
+
+            return new ContentResult
+            {
+                StatusCode = (int)code,
+                Content = doc.OuterXml,
+                ContentType = "text/xml"
+            };
+        }
+
+        public static Func<IActionResult> XmlFuture(HttpStatusCode code, IXMLEntity xml)
+        {
+            var doc = new XmlDocument();
+            var firstChild = xml.Serialize(doc);
+            doc.AppendChild(firstChild);
+            var serialized = doc.OuterXml;
+
+            return () =>
+            {
+                return new ContentResult
+                {
+                    StatusCode = (int)code,
+                    Content = serialized,
+                    ContentType = "text/xml"
+                };
+            };
+        }
+    }
+}