Support log retrieval on MultiKueue

[rochaporto]

What would you like to be added:

We would like to be able to retrieve logs from MultiKueue workloads, directly from the master cluster.

Why is this needed:

Multiple tools running on top of Kubernetes rely on the log retrieval API to give live feedback to users.

Examples include:

• The GitLab CI Kubernetes executor (https://docs.gitlab.com/runner/executors/kubernetes/) relies on the logs functionality to provide CI job logs to the users
• The Kubeflow jobs also integrate with log retrieval to display live feedback to users in the different dashboards ()

Completion requirements:

This enhancement requires the following artifacts:

• Design doc
• API change
• Docs update

The artifacts should be linked in subsequent comments.