chore: consolidate and refactor labels for pipelines

[ChunyiLyu]

Context

Workflow Pod names are non-deterministic. People need to use label selectors to be able to follow logs.

This chore asks:

1. rethink the set of labels we are applying to pipeline pods. Are they intuitive and k8s native?
2. refactor these labels if they can be improved
3. document these labels in https://docs.kratix.io/ especially in the troubleshooting page so users are aware how to use them for getting workflow logs.

[alparslanavci]

The PR ready, and we also created a follow-up task to remove the legacy labels.