Try to improve ConnectAsync for modern .NET

[WojciechNagorski]

For SshClient.ConnectAsync we should try to use a new native method instead of custom extensions.

ConnectAsync https://learn.microsoft.com/en-us/dotnet/api/system.net.sockets.socket.connectasync?view=net-7.0#system-net-sockets-socket-connectasync(system-net-endpoint-system-threading-cancellationtoken)

ReceiveAsync https://learn.microsoft.com/en-us/dotnet/api/system.net.sockets.socket.receiveasync?view=net-7.0#system-net-sockets-socket-receiveasync(system-memory((system-byte))-system-net-sockets-socketflags-system-threading-cancellationtoken)

It would be great to provide benchmark results

FYI @Rob-Hague @dmilosz

[WojciechNagorski]

The 2023.0.1 version has been released to Nuget: https://www.nuget.org/packages/SSH.NET/2023.0.1