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/Services/IUpdateUploader.cs

@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+
+namespace FSO.Server.Api.Core.Services
+{
+    public interface IUpdateUploader
+    {
+        Task<string> UploadFile(string destPath, string fileName, string groupName);
+    }
+}