Create InvisibleAction to be consumed by the JUnit

[v1v]

What

@mdelapenya and @v1v have been discussing recently about extending the JUnit plugin to provide further context about the tests. And in order to do so, it will be great if this plugin could provide some context for the JUnit step that could be consumed by the extension (so far the extension is something we are gonna build in an independent plugin as we are solving a particular use case in our end).

Proposal

Similar to #214, we would like the junit step to create an action with some details such as:

• Stage name
• Worker name or labels

Therefore the extension could consume it in order to enrich with some metadata the processed tests as spans attributes.

What do you think? Do you need more clarity about the problem statement?

[v1v]

Proof of concept: #216

[v1v]

Stage Name is accessible within the JUnit context:

• https://github.com/jenkinsci/junit-plugin/blob/d12130f23b408901e20f7007cfc2942e9bdb62bd/src/main/java/hudson/tasks/junit/pipeline/JUnitResultsStepExecution.java#L121-L137
• And Remove/deprecate checksName parameter to junit step junit-plugin#210

Worker name or labels:

• I think that's accessible with workspace.toComputer() then https://javadoc.jenkins-ci.org/hudson/model/Computer.html#getHostName-- could be the way to gather those details