Turn on and off DECCKM to modify keyboard mode for unix native commands to work correctly

[SteveL-MSFT]

PR Summary

Dotnet runtime sets keyboard mode to application on Unix systems and does not currently reset on exit. This change emits the DECRTS 1 sequence on pwsh exit on Unix systems (if VT is supported and interactive) to put keyboard mode back to default so that arrow keys do not emit escape sequences.

In the case of an interactive shell, we turn on DECCKM before showing prompt and turn if off before execution. This follows what zsh does.

Validated manually with gh auth login works with these changes and fails without.

PR Context

Fix #12268

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[iSazonov]

It is not full fix for #12268
We need to address external applications run. See #12268 (comment)

[SteveL-MSFT]

I'll update to set and reset in the native command processor

[iSazonov]

Start-Process?

[SteveL-MSFT]

@iSazonov it seems that if we follow zsh, then the set/reset should be in console host repl loop and not in native command processor nor start-process.

[iSazonov]

1. Why do we only Unix fix if the issue was reported as Windows bug?
2. I still think we could safely skip s_theConsoleHost.IsInteractive check.

[SteveL-MSFT]

@iSazonov it's not a Windows bug, it was WSL. .NET on Windows doesn't use ANSI escape sequences for keyboard input. As for why check for interactive, the problem is that if you do something like: pwsh -command 1, then you get back 1ESC[?1l as the output from that command. Even if you don't explicitly use -noninteractive the console host knows that -command without -noexit is non-interactive so we don't want to emit the ESC sequence that will be part of the stdout output.

[ghost]

This pull request has been automatically marked as Review Needed because it has been there has not been any activity for 7 days.
Maintainer, please provide feedback and/or mark it as Waiting on Author

[ghost]

🎉v7.2.0-preview.5 has been released which incorporates this pull request.:tada:

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