Allow custom "abort" text

[giannello]

Allow customizing the "Abort" text to better match the context, just like with "Proceed"

This supersedes #54

Solves JENKINS-66820

Testing done

Extended the existing automated tests

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
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• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[jglick]

No default, yet getCancel is setting a default. I think this means that snippet generator will suggest a cancel parameter even if you did not touch this option, which is undesirable: parameters proposed for the Groovy form of the step should include solely those fields which you actually edited from the default. Docs

[giannello]

That doesn't seem to be the case. I have deployed my custom HPI to our jenkins instance (Version 2.452.3 with all plugins up-to-date), and the behaviour is as following:
default when selecting the "input" sample step and clicking "Generate pipeline script"

after expanding "advanced" and clicking "generate pipeline script"

Adding a custom "cancel" caption

Adding a custom "OK" caption

Adding both

[giannello]

@strangelookingnerd @MarkEWaite @dwnusbaum sorry for the broad ping. This PR is 2 months old, can anybody give it a review?

[giannello]

@strangelookingnerd @MarkEWaite @jglick pinging again: is there anything missing for this to be merged/released? I would really love to get this done :)

[jglick]

I can ask around if there are any plugin maintainers watching.