Websocket refactoring (#190)

Websocket refactoring

CryptoExchange.Net/Interfaces/ICryptoRestClient.cs

@@ -0,0 +1,34 @@
+using CryptoExchange.Net.Interfaces.CommonClients;
+using Microsoft.Extensions.DependencyInjection;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace CryptoExchange.Net.Interfaces
+{
+    /// <summary>
+    /// Client for accessing REST API's for different exchanges
+    /// </summary>
+    public interface ICryptoRestClient
+    {
+        /// <summary>
+        /// Get a list of all registered common ISpotClient types
+        /// </summary>
+        /// <returns></returns>
+        IEnumerable<ISpotClient> GetSpotClients();
+
+        /// <summary>
+        /// Get an ISpotClient implementation by exchange name
+        /// </summary>
+        /// <param name="exchangeName"></param>
+        /// <returns></returns>
+        ISpotClient? SpotClient(string exchangeName);
+
+        /// <summary>
+        /// Try get 
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <returns></returns>
+        T TryGet<T>(Func<T> createFunc);
+    }
+}