Included PaymentStateMachine from TB

Breeze/src/Breeze.TumbleBit.Client/ExternalServices.cs

+using System;
+using System.Collections.Generic;
+using System.Text;
+using NBitcoin;
+using NTumbleBit;
+
+namespace Breeze.TumbleBit.Client
+{
+    public class ExternalServices
+    {
+        public Transaction FundTransaction(TxOut txOut, FeeRate feeRate)
+        {
+            return null;
+        }
+
+        public void Track(Script scriptPubkey)
+        {
+        }
+
+        public bool Broadcast(Transaction tx)
+        {
+            return true;
+        }
+
+        public void TrustedBroadcast(int cycleStart, TransactionType transactionType, uint correlation, TrustedBroadcastRequest broadcast)
+        {
+        }
+
+        public TransactionInformation[] GetTransactions(Script scriptPubKey, bool withProof)
+        {
+            return null;
+        }
+
+        public FeeRate GetFeeRate()
+        {
+            return null;
+        }
+    }
+}

Breeze/src/Breeze.TumbleBit.Client/TransactionType.cs

+namespace Breeze.TumbleBit.Client
+{
+    public enum TransactionType : int
+    {
+        TumblerEscrow,
+        TumblerRedeem,
+        /// <summary>
+        /// The transaction that cashout tumbler's escrow (go to client)
+        /// </summary>
+        TumblerCashout,
+
+        ClientEscrow,
+        ClientRedeem,
+        ClientOffer,
+        ClientEscape,
+        /// <summary>
+        /// The transaction that cashout client's escrow (go to tumbler)
+        /// </summary>
+        ClientFulfill,
+        ClientOfferRedeem
+    }
+}

Breeze/src/Breeze.TumbleBit.Client/TumblingState.cs

@@ -13,7 +13,7 @@ using Stratis.Bitcoin.Wallet;
 
 namespace Breeze.TumbleBit.Client
 {
-    public class TumblingState : IStateMachine
+    public partial class TumblingState : IStateMachine
     {
         private const string StateFileName = "tumblebit_state.json";