Support direct execution of ssh -t user@host docker exec -it xxx bash without falling back to host shell

[xiaoyaolangzhi]

This issue requests support for executing docker exec -it directly over SSH with proper TTY allocation, mimicking the behavior of the native command: ssh -t user@host docker exec -it xxx bash.

[Rob-Hague]

It should not be too hard, I guess it could be a new method CreateCommandWithTerminal as a mirror of CreateShellStreamNoTerminal with a call like

SSH.NET/src/Renci.SshNet/ShellStream.cs

Lines 91 to 94 in e5ad82c

	if (!_channel.SendPseudoTerminalRequest(terminalName, columns, rows, width, height, terminalModeValues))
	{
	throw new SshException("The pseudo-terminal request was not accepted by the server. Consult the server log for more information.");
	}