Optimization of API calls within DeviceSession

- replacing all API calls with new method "API" to cover APIRequestExceptions
- adding IDeviceSession interface for future use
- adding "API" method without result

TelegramBotBase/Interfaces/IDeviceSession.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using TelegramBotBase.Form;
+
+namespace TelegramBotBase.Interfaces
+{
+    interface IDeviceSession
+    {
+        /// <summary>
+        /// Device or chat id
+        /// </summary>
+        long DeviceId { get; set; }
+
+        /// <summary>
+        /// Username of user or group
+        /// </summary>
+        String ChatTitle { get; set; }
+
+
+        /// <summary>
+        /// When did any last action happend (message received or button clicked)
+        /// </summary>
+        DateTime LastAction { get; set; }
+
+        /// <summary>
+        /// Returns the form where the user/group is at the moment.
+        /// </summary>
+        FormBase ActiveForm { get; set; }
+
+        /// <summary>
+        /// Returns the previous shown form
+        /// </summary>
+        FormBase PreviousForm { get; set; }
+
+        /// <summary>
+        /// contains if the form has been switched (navigated)
+        /// </summary>
+        bool FormSwitched { get; set; }
+
+    }
+}