Add --no-pager option in help command

[silvanocerza]

Summary

Fixes #4941.

This PR adds a --no-pager option in help command to explicitly disable the pager.

I noted that the template used for the text printed when calling help with no argument or option doesn't show any option. It made sense before this PR since help didn't have any available option. Though I'm unsure if it makes sense to update the template as it would make it extremely verbose as all the global options would be shown too.

I leave the decision to you.

Test Plan

I ran cargo run -- help to verify --isolated was visible and it.
I ran clippy with cargo clippy --workspace --all-targets --all-features --locked -- -D warnings as CI does.

I also ran tests locally with:

cargo nextest run \
            --features python-patch \
            --workspace \
            --status-level skip --failure-output immediate-final --no-fail-fast -j 12 --final-status-level slow

[zanieb]

Maybe we should collapse these into a should_page bool haha it's getting kind of long.

[silvanocerza]

Will do! 👍

[zanieb]

I noted that the template used for the text printed when calling help with no argument or option doesn't show any option.

Hm yeah this is tough. We may need to manually write out the help template so it includes the options for the command? Unless there's a way to turn off the global options (I don't think there is)

[zanieb]

We never page for the root command so --no-pager should have no effect here (we also can't page during snapshots so it's kind of moot).

[silvanocerza]

Should I remove the test then?

[zanieb]

Seems nice to confirm that the option exists and works. Maybe just add a comment noting that we can't actually check if the pager is used?

[zanieb]

Thanks for contributing! Congrats on the first pull request :)

[silvanocerza]

Hm yeah this is tough. We may need to manually write out the help template so it includes the options for the command? Unless there's a way to turn off the global options (I don't think there is)

Looking at the template documentation doesn't seem like there's a way to separate them. 😕

[silvanocerza]

Fixed all the things you pointed out.

I also rebased to bring the changes from #5005 or the new test would have failed right after merging in main.