feat: add new kube_service_spec_ports metric

[Serializator]

What this PR does / why we need it:
Add new metric kube_service_spec_ports to represent ports on the service resource.

The kube_service_spec_ prefix matches with the naming convention for the rest of the metrics.

To stay aligned with other metrics, .spec.ports.appProtocol is not included as a label. The same is true for the kube_endpoint_address metric.

.spec.ports.targetPort is not included as a label due to its inconsistent value. It can be a named port or port number.

How does this change affect the cardinality of KSM:
Increases cardinality with a new time series.

Which issue(s) this PR fixes:
Fixes #2819

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[k8s-ci-robot]

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[Serializator]

Hey @dgrisonnet & @mrueg! Would one of you have time to approve the workflow so tests can run? Thank you in advance!