Add labels to the Workload object matching the job details

[alculquicondor]

What would you like to be added:

The name of a Workload doesn't match the name of the Job, to avoid collisions among different CRDs.

As a result, it's hard to quickly obtain the Workload for a particular job. A pair of labels (for name and GVK) would make it feasible to query.

Why is this needed:

For general usability and also to efficiently implement a CLI that gives you all relevant information for a job #487

Completion requirements:

This enhancement requires the following artifacts:

• Design doc
• API change
• Docs update

The artifacts should be linked in subsequent comments.

[achernevskii]

/assign

[trasc]

isn't the owner reference sufficient?

[alculquicondor]

It's sufficient for a controller (like kueue) which watches every Workload object and is able to maintain an index.
OTOH, a CLI would have to call List and filter client-side to find the corresponding workload. A label allows to do the filtering server-side.