Getter methods for ArgGroup.

[aobatact]

Please complete the following tasks

• I have searched the discussions
• I have searched the open and rejected issues

Clap Version

3.2.22

Describe your use case

While I'm working with adding a Serialize impl at aobatact/clap-serde#46, I wanted to get the value from ArgGroup to serialize.

Describe the solution you'd like

Add a getter methods to ArgGroup like get_args and is_mutiple.

Alternatives, if applicable

No response

Additional Context

No response

[tony-go]

Hi 👋

Is this a valid entry point for this issue? https://github.com/clap-rs/clap/blob/master/src/builder/arg_group.rs

[epage]

That is the file that would need to be updated for this issue, yes

[tony-go]

Hey @aobatact 👋

I'm trying to make my first Rust contribution. And as we used Clap in the RIA book, I was looking forward to resolving an issue here ^^

Maybe you plan to tackle this issue yourself? Otherwise, I'll happy to help. :)

[aobatact]

Hi @tony-go !

I don't have time to be involved in this right now and would be happy if you could help with this.