Enable PR-tester per PR comments to help the verification process

Github actions only support limited platforms. For non supported platforms usually developers or reviewers will run jenkins jobs, e.g [grinder](https://ci.adoptium.net/view/Test_grinder/job/Grinder/) to verify. To make this process easier developers or reviewers can just do comments to trigger specified jenkins job. jenkins job result can also be updated to corresponding PR or issues.

Start by examining the repository's existing GitHub Actions configuration and the linked Grinder Jenkins job. Define how a pull-request comment selects and triggers a Jenkins job, and how its result is reported back to the pull request or issue; the feature is done when this workflow is specified and works for unsupported platforms.

Written by the indexing model from the issue text.