Feature: Sharing data using the InvocationContext

[tmds]

Can you something similar to HttpContext.Items which enables sharing data between different methods that work on the InvocationContext?

public class InvocationContext
{
     public IDictionary<string, object> Items { get; }
}

My request comes from wanting to break up handling into several steps.
This provides a way to pass data between the steps.

I can imagine, you could also use this to track things like a ConfigurationManager or an IServiceCollection, enabling to implement configuration or dependency injection external to the core System.CommandLine package.

cc @jonsequitur @adamsitnik @KathleenDollard

[tmds]

A more generic version of this, would be to allow creating a derived class of InvocationContext and have the invocation use that.

public class MyInvocationContext : InvocationContext
{
    public MyInvocationContext(ParseResult parseResult, IConsole? console = null)
           : base(parseResult, console) { }

    // public IDictionary<string, object> Items { get; }
    // or anything else
}

Then call something like the following (on what?) to create the derived type instead of the default InvocationContext.

void UseInvocationContextClass<T>(Func<ParseResult, IConsole?, InvocationContext> invocationContextFactory);

[tmds]

A more generic version

Actually, this is not the case. The Items enable independent users to add something. While a derived type will only serve a specific set of users.

[tmds]

Replaced by #2090.