Assign alerts on core components directly to turtles

[weseven]

Towards giantswarm/roadmap#2728 / https://github.com/giantswarm/giantswarm/issues/31439

This PR assigns alerts on basic components to turtles directly.

Checklist

• Update CHANGELOG.md
• Add Unit tests
• Follow Alert structure
• Consider creating a dashboard (guidelines) (if it does not exist already) to help oncallers monitor the status of the issue.
• Request review from oncall area, as well as team (e.g: oncall-kaas-cloud GitHub group).

[fiunchinho]

These all look good. Why don't we move all of the alerts on the turtles folder though? If they don't belong to turtles, they should be moved to a different folder. But if they do, I believe turtles should get paged by it.