Add issue / pull request number option

[miguelaferreira]

Thanks for this really nice action! We have been using it a lot and really like it.

We've started to use this action to post results of deployment tests, and while we get the test results in the github action workflow summary, We don't get them in the pull requests nor issues that trigger the deployment.

We have two use cases:

1. Deploy a release candidate from a PR:

• On the PR we add a label deploy, that run a workflow that creates a release candidate git tag;
• Then the tag triggers a deployment workflow that deploys the release candidate;
• After deployment we run a tool that tests it;
• That tool produces an XML output that this action can read;
• Then the action posts the test results in the workflow summary;
• What we're missing is: to have the action also posts the test results in the PR where it all started to begin with.

3. Deploy a final release from an issue:

• Once code gets merged to main branch, a workflow creates a final release git tag;
• That tag triggers the creation of a deployment issue, basically an issue with a specific format that we use to deploy final releases to different environments in sequence;
• Once we comment deploy tst on the deployment issue, a workflow starts the deployment of the release to our TST environment.
• After deployment we run a tool that tests it;
• That tool produces an XML output that this action can read;
• Then the action posts the test results in the workflow summary;
• What I'm missing is: to have the action also posts the test results in the PR where it all started to begin with.

So, what we are asking in this issue is to have a way to provide the issue/pr ID to the action, in order for it to post to issues/pull requests (respectively).