* Added protection from NotImplementedException to HandlerBuilderBase

* Moved AddHandler<T> and AddHandler(Type) methods from IHandlersCollection to extension methods
* Added public constructor to IHost types form extensibility
* Code cleanup

Telegrator.Hosting/Providers/Components/IHostHandlersCollection.cs

@@ -0,0 +1,16 @@
+using Telegrator.MadiatorCore;
+
+namespace Telegrator.Hosting.Providers.Components
+{
+    /// <summary>
+    /// Collection class for managing handler descriptors organized by update type for host apps.
+    /// Provides functionality for collecting, adding, scanning, and organizing handlers.
+    /// </summary>
+    public interface IHostHandlersCollection : IHandlersCollection
+    {
+        /// <summary>
+        /// List of tasks that should be completed right before building the bot
+        /// </summary>
+        public List<PreBuildingRoutine> PreBuilderRoutines { get; }
+    }
+}