Fixes #7691

From the k8s docs:

// loadBalancerClass is the class of the load balancer implementation this Service belongs to.
// If specified, the value of this field must be a label-style identifier, with an optional prefix,
// e.g. "internal-vip" or "example.com/internal-vip". Unprefixed names are reserved for end-users.
// This field can only be set when the Service type is 'LoadBalancer'. If not set, the default load
// balancer implementation is used, today this is typically done through the cloud provider integration,
// but should apply for any default implementation. If set, it is assumed that a load balancer
// implementation is watching for Services with a matching class. Any default load balancer
// implementation (e.g. cloud providers) should ignore Services that set this field.
// This field can only be set when creating or updating a Service to type 'LoadBalancer'.
// Once set, it can not be changed. This field will be wiped when a service is updated to a non 'LoadBalancer' type.

AWS EKS uses this field on EKS clusters > 1.24 that have upgraded to the new AWS LoadBalancer Controller

Behaviour this PR should implement:

• default the loadBalancerClass from the server side values if no value is set in the ECK service spec
• recreate the service if the value set in the ECK service spec differes from the server side value
• allow resetting the value only if the type of the service is no longer LoadBalancer