Support setting NamedPipeClientStream.ReadMode with PipeAccessRights ctor overload

[jeffhandley]

Fixes #83072 (Cannot set ReadMode after creating a NamedPipeClientStream instance).

Per the API Review notes and video:

1. Add the missing constructor to NamedPipeClientStream that accepts PipeAccessRights
2. Promote PipeAccessRights from System.IO.Pipes.AccessRights to System.IO.Pipes, and add the necessary type-forward
3. Mark the constructor as being only supported on Windows, but leave the enum available on all platforms
4. Review for nullability annotations -- no arguments allow null

The .NET Framework implementation was referenced from Pipe.cs, but the behavior was improved slightly.

• Argument validation logic is reused rather than being duplicated into the new constructor
• The direction argument is given a valid value when the desiredAccessRights value is invalid, ensuring that the correct desiredAccessRights argument exception is thrown
  • In netfx, any desiredAccessRights value missing both the ReadData (1) and WriteData (2) bits would throw an argument exception for direction, which is not an argument to the constructor
• Argument validation for desiredAccessRights also throws for a 0 value, which netfx didn't do

The functionality was tested using the following server / client apps:

server.cs

using System.IO.Pipes;

var pipeOut = new NamedPipeServerStream("SomeNamedPipe",
                                        PipeDirection.Out,
                                        1,
                                        PipeTransmissionMode.Message);

Console.WriteLine("Waiting for a connection...");
pipeOut.WaitForConnection();

Console.WriteLine("Connected. Sending messages...");

while (true) {
    pipeOut.Write("Hello "u8);
    pipeOut.Write("from "u8);
    pipeOut.Write("the "u8);
    pipeOut.Write("server!"u8);

    Console.WriteLine("Messages sent. Sleeping for 10 seconds.");
    System.Threading.Thread.Sleep(10_000);
}

client.cs

using System.IO.Pipes;

var pipeIn = new NamedPipeClientStream(".",
                             "SomeNamedPipe",
                             PipeAccessRights.ReadData | PipeAccessRights.WriteAttributes,
                             PipeOptions.None,
                             System.Security.Principal.TokenImpersonationLevel.None,
                             System.IO.HandleInheritability.None);

pipeIn.Connect();
pipeIn.ReadMode = PipeTransmissionMode.Message;

while (pipeIn.IsConnected)
{
    var buffer = new byte[2];
    var bytesRead = pipeIn.Read(buffer, 0, buffer.Length);

    if (bytesRead > 0) {
        var message = System.Text.Encoding.UTF8.GetString(buffer, 0, bytesRead);
        Console.Write(message);

        System.Threading.Thread.Sleep(1000);

        if (pipeIn.IsMessageComplete) {
            Console.WriteLine();
        }
    }
}

With this PR, that application works as expected, with the client detecting completed messages after each word and rendering newlines.

[ghost]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[stephentoub]

Other than the comments on tests, LGTM. Thanks.

[carlossanlop]

Looks good so far, thanks! Please also add some tests proving the new API works as expected.

[carlossanlop]

Thanks! Left some more suggestions for you to consider.

[carlossanlop]

LGTM!
And thanks for also moving those unrelated windows and unix tests to their own file, even thought they were not part of the PR.