[Bug] pipe name wrongly created on Windows, preventing access to any database

[OhSoGood]

Steps to reproduce

Try to access any Mysql/Mariadb database on Windows with named pipes with Pomelo. You will get an exception.

The issue

OpenNamedPipeAsync in ServerSession.cs wrongly creates a pipe name with format (host)\pipe(pineName) with these lines:

	// see https://docs.microsoft.com/en-us/windows/win32/ipc/pipe-names for pipe name format
	var pipeName = @"\\" + cs.HostNames![0] + @"\pipe\" + cs.PipeName;
	[...]
	var namedPipeStream = new NamedPipeClientStream(cs.HostNames![0], cs.PipeName, PipeDirection.InOut, PipeOptions.Asynchronous);

But NamedPipeClientStream actually does the same thing internally, leading to a wrong pipename. Proof:

string pipHost = ".";

 // TimeoutException
pipName = @"\\.\pipe\MySQL";
using var pipe = new System.IO.Pipes.NamedPipeClientStream(pipHost, pipName, System.IO.Pipes.PipeDirection.InOut, System.IO.Pipes.PipeOptions.Asynchronous);
pipe.Connect(2_000);

 // Connect immediately
pipName = "MySQL";
using var pipe = new System.IO.Pipes.NamedPipeClientStream(pipHost, pipName, System.IO.Pipes.PipeDirection.InOut, System.IO.Pipes.PipeOptions.Asynchronous);
pipe.Connect(2_000);

The solution is simply to change the line: var pipeName = @"\\" + cs.HostNames![0] + @"\pipe\" + cs.PipeName; into var pipeName = cs.PipeName;

Further technical details

MySQL version: Operating system: Windows Pomelo.EntityFrameworkCore.MySql version: 7.0.0 Microsoft.AspNetCore.App version: 6.0.x