Missing port information in service metrics

[jonsbun]

What would you like to be added:
It would be great to have a service metric that exposes port, similar to "kube_endpoint_ports" or "kube_endpointslice_ports" metrics.

Why is this needed:
Current service metrics are not accurately reflecting one of the most important aspects of service.

Describe the solution you'd like:
Add additional metric like "kube_service_ports".

Additional context:
n/a

[dgrisonnet]

/triage accepted
/assign @mrueg