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/Cache/ICache.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Threading.Tasks;
+
+namespace FSO.Common.Utils.Cache
+{
+    public interface ICache : IDisposable
+    {
+        bool ContainsKey(CacheKey key);
+        void Add(CacheKey key, byte[] bytes);
+        void Remove(CacheKey key);
+
+        Task<T> Get<T>(CacheKey key);
+
+        //bool IsReady { get; }
+        //bool Contains(string type, string key);
+        //Task<byte[]> GetBytes(string type, string key);
+        //Task PutBytes(string type, string key, byte[] bytes);
+        //Task Init();
+    }
+}