Separate parse from invocation configurations

[jonsequitur]

This PR's goal is to separate the CommandLineConfiguration class into two separate classes, one of which configures parsing behaviors (now called ParserConfiguration) and the other of which configures invocation behaviors (InvocationConfiguration). InvocationConfiguration has four properties which were moved over from CommandLineConfiguration:

• EnableDefaultExceptionHandler
• ProcessTerminationTimeout
• Output
• Error

I've also removed the Parse, Invoke, and InvokeAsync methods from the former CommandLineConfiguration, since they're also available on ParseResult. The redundancy seemed unnecessary, although these invoke methods did include a Parse call, making the calling pattern more like the old, more succinct Command.Invoke methods.

Next steps:

• In light of these changes, I think both of these classes need better names.
• I think that passing a RootCommand to the CommandLineConfiguration constructor should not be necessary, and can lead to some unclear situations, such as:

var rootCommand = new RootCommand
{
    new Option<string>("-x")
};

var result = rootCommand.Parse(
    "-x which-root-command-controls-the-parser",
    new CommandLineConfiguration(
        new RootCommand
        {
            new Option<string>("-y")
        }));

[KalleOlaviNiemitalo]

I was going to comment that a suggest directive or a help action would need to be able to read the parsing configuration at invocation time, such as EnablePosixBundling. But I see ParseResult does have public properties for both configurations.

[adamsitnik]

Overall it LGTM, but please see my comments with some suggestions for improvements. Thank you @jonsequitur !

[adamsitnik]

I am hitting the approve button to get you unblocked @jonsequitur , but please address my comment about Invoke before merging. Thanks a lot!

[AlexandreEXFO]

@jonsequitur, @adamsitnik, @jefferson-lam: This change in the contract between 2.0.0-beta6 and 2.0.0-beta7 should be documented as it was when breaking changes were introduced in 2.0.0-beta5.

https://learn.microsoft.com/en-us/dotnet/standard/commandline/migration-guide-2.0.0-beta5

I had to dig into the code to find what had been changed.

[AlexandreEXFO]

Hope this helps someone who is having the same problem.

Before

await new CommandLineConfiguration(rootCommand).InvokeAsync(args);

After

await rootCommand.Parse(args).InvokeAsync();