Added EndPoint RemoteEndPoint {get;} property to channel (#2111)

* Added EndPoint RemoteEndPoint{get;} property

* Reformat code

* Reformat code

---------

Co-authored-by: christian <6939810+chkr1011@users.noreply.github.com>

Source/MQTTnet.Server/Events/InterceptingPacketEventArgs.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections;
+using System.Net;
 using System.Threading;
 using MQTTnet.Packets;
 
@@ -11,11 +12,11 @@ namespace MQTTnet.Server
 {
     public sealed class InterceptingPacketEventArgs : EventArgs
     {
-        public InterceptingPacketEventArgs(CancellationToken cancellationToken, string clientId, string endpoint, MqttPacket packet, IDictionary sessionItems)
+        public InterceptingPacketEventArgs(CancellationToken cancellationToken, string clientId, EndPoint remoteEndPoint, MqttPacket packet, IDictionary sessionItems)
         {
             CancellationToken = cancellationToken;
             ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
-            Endpoint = endpoint;
+            RemoteEndPoint = remoteEndPoint;
             Packet = packet ?? throw new ArgumentNullException(nameof(packet));
             SessionItems = sessionItems;
         }
@@ -34,7 +35,10 @@ namespace MQTTnet.Server
         /// <summary>
         ///     Gets the endpoint of the sending or receiving client.
         /// </summary>
-        public string Endpoint { get; }
+        public EndPoint RemoteEndPoint { get; }
+
+        [Obsolete("Use RemoteEndPoint instead.")]
+        public string Endpoint => RemoteEndPoint?.ToString();
 
         /// <summary>
         ///     Gets or sets the MQTT packet which was received or will be sent.