Improve performance and drop support for old frameworks (#2068)

* Remove WebSocket4Net extension library

* Remove UWP support

* Drop support for all old frameworks

* Update CI

* Update CI

* Update CI

* Update CI

* Remove obsolete code

* Set default protocol version to 5.0.0

* Remove obsolete tests

* Remove old dependencies

* Reset release notes

* Move server to dedicated project

* Fix unit tests

* Update and cleanup nuget packages

* Fix unit tests
Refactor code

* No longer throw exception when receiving non success CONNACK

* Enable nuget signing

* Enable nuget signing

* Enable nuget signing

* Enable nuget signing

* Enable nuget signing

* Enable nuget signing

* Enable nuget signing

* Enable nuget signing

* Enable code signing

* Enable code signing

* Enable code signing

* Fix client endpoint handling

* Improve CI

* Fix CI

* Fix CI

* Fix CI

* Fix CI

* Import changes from version 4

* Cleanup target frameworks and remove obsolete code

* Drop support for dotnet7.0

* Remove managed client

* Version5 auditmode (#2016)

Added NuGet audit mode and some other settings to get informed about security issues.

* Address warnings from analyzers

* Support for ReadOnlySequence as payload (#2046)

* use ReadOnlySequence as payload

* fix build

* fix build

* skip sign in forks

* remove unnecessary owner

* tests and extensions

* remove test

* simplify WritePacketBuffer, remove unused helper

* Adjust namespaces

* Fix build errors

* Import latest fixes from main branch

* Adjust namespaces

---------

Co-authored-by: SeppPenner <HansM2013@gmx.de>
Co-authored-by: Martin Regen <mregen@microsoft.com>

Samples/Server/Server_Intercepting_Samples.cs

@@ -22,10 +22,10 @@ public static class Server_Intercepting_Samples
          * Please see _Server_Simple_Samples_ for more details on how to start a server.
          */
 
-        var mqttFactory = new MqttFactory();
+        var mqttServerFactory = new MqttServerFactory();
         var mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
 
-        using (var mqttServer = mqttFactory.CreateMqttServer(mqttServerOptions))
+        using (var mqttServer = mqttServerFactory.CreateMqttServer(mqttServerOptions))
         {
             mqttServer.InterceptingPublishAsync += args =>
             {