ANSI colors under Windows

[knutwannheden]

When I run jbang under Windows I either don't get any ANSI colors (when running using cmd.exe or powershell.exe) or ANSI escape sequences end up cluttering my screen.

AFAICT Picocli should be able to work properly even on Windows but probably requires Jansi (see https://picocli.info/#_windows).

I couldn't find any Jansi dependency in jbang, but I could try work out a PR, if you think adding this dependency would be acceptable.

/cc @maxandersen

[quintesse]

If it is something that is not overly big and can be integrated in the jbang.jar then I don't see any problem with including that dependency. Quite the contrary, it would be nice to see colors on Windows!

[knutwannheden]

At the moment the ANSI escape codes just garble the output to the point that it is hard to read, when running under Git Bash, because Picocli's heuristics think that colors should be working.

I will look into it.

[knutwannheden]

A simple test confirms that just calling AnsiConsole.systemInstall() in Main#main fixes the issue.

[knutwannheden]

The following PR should address the issue: #1256