Enhance troubleshooting to understand if a job is actually running

[alculquicondor]

What would you like to be added:

This question just refers to whether the job is suspended https://kueue.sigs.k8s.io/docs/tasks/troubleshooting/troubleshooting_jobs/#is-my-job-running

In some cases, the suspend field can be false, while the pods are unschedulable.

It would be useful to make the distinction.

Why is this needed:

Users don't necessarily understand the separation of concerns between kueue and kube-scheduler or cluster-autoscaler. We need to direct them to ask the right questions.

Completion requirements:

This enhancement requires the following artifacts:

• Design doc
• API change
• Docs update

The artifacts should be linked in subsequent comments.

[tenzen-y]

/remove-kind feature
/kind documentation

[alculquicondor]

/assign