Fix links to documentation describing the Prometheus service and its specifics.

Add more info about Prometheus service configuration, and fixing problems with missing labels

Why was this MR needed?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #34598 (closed)