Add Post terminator args support

[malko]

This PR addresses #1895, adding an easy way to ignore args after the arg terminator --. It also add easy retrieving of such arguments to easily manipulate them. It is an optin feature, without setting IgnorePostTerminatorArgs to true it should not change anything, so no breaking change.

this PR includes:

• Adding a field IgnorePostTerminatorArgs to the Command struct
• Adding a method PostTerminatorArgs to the Command struct
• test we don't break normal behaviour such as args validation
• documentation for the added feature

Hope this can be of any help to others.

[CLAassistant]

All committers have signed the CLA.

[github-actions[bot]]

This PR exceeds the recommended size of 200 lines. Please make sure you are NOT addressing multiple issues with one PR. Note this PR might be rejected due to its size.

[github-actions[bot]]

This PR exceeds the recommended size of 200 lines. Please make sure you are NOT addressing multiple issues with one PR. Note this PR might be rejected due to its size.

[malko]

Is there any chance for that to be part of next release ?

[adrian-gierakowski]

I would really like to use this. Any chance for getting it accepted and released?

[malko]

@adrian-gierakowski waiting for this since march 2023, the PR is now conflicting :cry: .

I'm ok to make the extra work to get rid of conflict if this is not more that the user_guide.md to change, but the more maintainers wait to review this the more work risks to arise. What i'm trying to say, is that I won't make any more work on this until an official maintainer ask for it. This PR took me a lot of time, and for now even if I understand that maintainers have a lot to review and do to maintain the project, it looks to me like I've wasted my times trying to propose a PR.

Hope future will prove me wrong.