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/tso.common/Utils/Promise.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace FSO.Common.Utils
+{
+    public class Promise <T>
+    {
+        private Func<object, T> Getter;
+        private T Value;
+        private bool HasRun = false;
+        
+
+        public Promise(Func<object, T> getter)
+        {
+            this.Getter = getter;
+        }
+
+        public void SetValue(T value)
+        {
+            this.HasRun = true;
+            this.Value = value;
+        }
+
+
+        public T Get()
+        {
+            if (HasRun == false)
+            {
+                Value = Getter(null);
+                HasRun = true;
+            }
+
+            return Value;
+        }
+    }
+}