Add custom operation useTokenReplacer

[AngelMunoz]

This adds a custom operation to allow us to by-pass a new SCL feature that takes any prefixed @ strings with certain configuration files more info here

I got some pointers from Chet to add a TryReplaceToken delegate so skip this token processing

I wasn't sure how to add a rootCommandTest for this change because it initializes a parser in the helper itself and the parser has to also have a TryReplaceToken delegate for it to work properly, so I added a manual test in the TestConsole project

[JordanMarr]

I wasn't aware of this feature, but I can see how this came up as an issue for Pearla.
Thanks for the PR.

[JordanMarr]

Haven't had my morning coffee yet, but after playing with your changes I just remembered that there is a usePipeline custom operation (suggested by Chet) that allows you to customize the builder/pipeline:

module ProgramTokenReplacer

open FSharp.SystemCommandLine
open System.CommandLine.Builder

let app (package: string) =
    if package.StartsWith("@") then
        printfn $"{package}"
        0
    else
        eprintfn "The package name does not start with a leading @"
        1

[<EntryPoint>]
let main argv =
    let package = Input.Option([ "--package"; "-p" ], "A package with a leading @ name")

    rootCommand argv {
        description "Can be called with a leading @ package"

        usePipeline (fun builder -> 
            // Skip @ processing
            builder.UseTokenReplacer(fun _ _ _ -> false)
        )
        
        inputs package
        setHandler app
    }

But I wonder if it would be worth adding something along the lines of disableTokenReplacer to do the same thing:

module ProgramTokenReplacer

open FSharp.SystemCommandLine

let app (package: string) =
    if package.StartsWith("@") then
        printfn $"{package}"
        0
    else
        eprintfn "The package name does not start with a leading @"
        1

[<EntryPoint>]
let main argv =
    let package = Input.Option([ "--package"; "-p" ], "A package with a leading @ name")

    rootCommand argv {
        description "Can be called with a leading @ package"

        disableTokenReplacer

        inputs package
        setHandler app
    }

[AngelMunoz]

Oh my... I didn't realize that was the intended use case for the pipeline my bad 😅! in that case then I don't think disableTokenReplacer is required at all it is a very trivial change to be honest I guess if this kind of issue pops up more often then It could be considered

[JordanMarr]

There was really no way for you to know. In fact, as I look at the readme, usePipeline is not even mentioned once. 😆
I think I will keep your ProgramTokenReplacer.fs example and put that in the readme as a use case for usePipeline for other people that have this problem.

[JordanMarr]

Added a section on customizing the pipeline with your example (as that may be an issue for someone else in the future):

Customizing the Default Pipeline