fix(api-server): add defaulter in MeshService and MeshMultizoneService

[lahabana]

Motivation

There are fields like targetPort on port name that default to another value if not set.
This can't be expressed with annotations so defaulting with a Defaulter is usefull in these cases.

Implementation information

There's an open question around what this would do with things like TF as the PUT and GET return something different.

[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)
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[lahabana]

If we go forward with this change we need to make sure the API docs are updated to explain this defaulting

[schogges]

LGTM so far 👍 left a Q on the golden files

[schogges]

I was wondering why some of the golden files include only empty objects? 🙂
From my understanding that's the expected response?

[lahabana]

The default response for a PUT returns an empty object, that's what this first reponse is.

[slonka]

Disclaimer: I only checked the description of that it supposed to do (not the code).

There is no other way if this can't be described by simply an annotation. In terraform this can be marked as "computed" and won't show up in the diff. So based on that 👍