Allow `nf-core download -r` to download commits

[fellen31]

Mimic the behaviour of nextflow run -r and allow selected commit(s) to be downloaded.

https://nfcore.slack.com/archives/CE5LG7WMB/p1712143905189639

Not sure about the effect it will have on Tower downloads.

PR checklist

• [ ] This comment contains a description of changes (with reason)
• [ ] CHANGELOG.md is updated
• [ ] If you've fixed a bug or added code that should be tested, add tests!
• [ ] Documentation in docs is updated

[mashehu]

@nf-core-bot fix linting

[fellen31]

@nf-core-bot fix linting

[ewels]

On hold until further notice. Nearly complete in case anyone wants to pick it up.

Suggestion is to guess the URL for the supplied commit (if it looks like a hash - is the right length and characters) and try it, see if we get a 404 or not. That way we don't need to fetch the commit history for the repo.

[github-actions[bot]]

This PR has been tagged as awaiting-changes or awaiting-feedback by an nf-core contributor. Remove stale label or add a comment if it is still useful.

[mirpedrol]

🧹 spring cleaning message 🌷

Closing this as it went stale

[mashehu]

Actually it was added in #3374 🙂