chore: ensure metrics are correctly exposed

[xeniape]

Description

Part of stackabletech/issues#747
This PR adds a metrics service with the additional Prometheus annotations. It also adds some documentation on monitoring for the TLS case since, similar to NiFi, HBase also exposes metrics behind a port which gets secured by TLS

Follow up monitoring Stack PR because moving to the metrics service, the port name changed: stackabletech/demos#316

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• CRD changes approved
• CRD documentation for all fields, following the style guide.
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible
• Links to generated (nightly) docs added
• Release note snippet added

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added
• Links to generated (nightly) docs added
• Release note snippet added
• Add type/deprecation label & add to the deprecation schedule
• Add type/experimental label & add to the experimental features tracker

[Techassi]

Looks mostly good to me, just some minor suggestions and a few questions.

I only looked at the Rust code - let me know if I should look at the docs as well.