Adds support for specifying specific IP for cloud provider load balancers

[jamesdbloom]

Summary

Adds support for specifying specific IP for cloud provider load balancers, see: https://kubernetes.io/docs/concepts/services-networking/service/\#loadbalancer or https://docs.microsoft.com/en-us/azure/aks/static-ip\#create-a-service-using-the-static-ip-address

Full changelog

• added ability to configure loadBalancerIP to for control plane service

Documentation

• documented in deployments/charts/kuma/values.yaml

Testing

• Manual testing on Kubernetes

Backwards compatibility

• Add backport-to-stable label if the code is backwards compatible. Otherwise, list breaking changes.

[jpeach]

Thanks @jamesdbloom ! Could you please sign your commit?

[jamesdbloom]

I realised it does not make sense to expose the normal service via a LoadBalancer as this is not allowed when there are multiple ports with different protocols (i.e. TCP and UDP).

I will update the PR and sign my commit once I have fully finished testing our deployment with multiple zones and a global cp in AKS (Azure).

[jamesdbloom]

Closing as raising new PR with signed commits and slightly improved approach