feat(inspect): api for retrieving service hostnames

[jakubdyszkiewicz]

Motivation

We want to see hostnames of Mesh*Service in the Global CP.

Implementation information

While we could add new KDSService to retrieve stats of a resource in specific zones and then aggregate this an easier (less expensive to execute, faster, don't depend on the zone) option is to calculate the hostname. We have all the resources in global CP already (because HostnameGenerator from zone is synced to global for visibility). It's just a matter of relabeling properly.

Supporting documentation

Fix #10618

[slonka]

In general ok, but missing some bits that would make it better.

[slonka]

LGTM - one nit

[github-actions]

Reviewer Checklist

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If something doesn't apply please check the box and add a justification if the reason is non obvious.

• Is the PR title satisfactory? Is this part of a larger feature and should be grouped using > Changelog?
• PR description is clear and complete. It Links to relevant issue as well as docs and UI issues
• This will not break child repos: it doesn't hardcode values (.e.g "kumahq" as an image registry)
• IPv6 is taken into account (.e.g: no string concatenation of host port)
• Tests (Unit test, E2E tests, manual test on universal and k8s)
  • Don't forget ci/ labels to run additional/fewer tests
• Does this contain a change that needs to be notified to users? In this case, UPGRADE.md should be updated.
• Does it need to be backported according to the backporting policy? (this GH action will add "backport" label based on these file globs, if you want to prevent it from adding the "backport" label use no-backport-autolabel label)