Add an option to predefine the IP of the internal passthrough load balancer

[RnkeZ]

trafficstars

/kind feature

Describe the solution you'd like Add an option to create a predefined static IP address for an internal passthrough load balancer.

Anything else you would like to add: When deploying a cluster, it is useful to know the static IP of the API server before the internal passthrough load balancer is created, especially for integration with certain third-party tools. This setup is similar to how private IPs are handled in other CAPI providers (such as CAPZ), where users can predefine the private IP of the load balancer.