[Feature] Expose APIServer Service provisioned by karmada-operator

[RainbowMango]

Background Currently, there is no reliable method to reference the Service for the Karmada APIServer. Users have to infer the Service based on internal implementation details, which can change over time, making this approach fragile and unreliable. This feature aims to provide a robust and stable way to expose Karmada services, particularly the APIServer, to external clusters or networks.

Proposal https://github.com/karmada-io/karmada/pull/5599

The goal of this feature is to enhance the karmada-operator to include the Karmada API Server Service information in the status of Karmada resource objects. This will provide a standardized and reliable way for third-party applications to discover and interact with the Karmada API Server Service. The feature will ensure that the service information is consistently available and up-to-date, regardless of internal implementation changes.

Iteration Tasks

• [x] Feature proposal. (@jabellard, #5599)
• [x] Restrict the supported ServiceType by adding some validations. (@RainbowMango, #5769)
• [x] Enable Service type : LoadBalancer. (@chaosi-zju, #5773)
  • The runUploadAdminKubeconfig() didn't handle service with type LoadBalancer.
• [ ] Feature implementation
  • [x] Code (@jabellard, https://github.com/karmada-io/karmada/pull/5775)
  • [x] Test (@jabellard, https://github.com/karmada-io/karmada/pull/5775)
  • [ ] Documentation
  • We should have a doc to introduce how to access the karmada-apiserver, like Access The Argo CD API Server

[RainbowMango]

@jabellard @chaosi-zju What do you think of having a doc for this feature? Let me know if you are going to help with it.