Support new `authentication_mode` config for eks_cluster

[z0rc]

Describe the Feature

https://aws.amazon.com/blogs/containers/a-deep-dive-into-simplified-amazon-eks-access-management-controls/ and https://docs.aws.amazon.com/eks/latest/userguide/access-entries.html#authentication-modes

Upcoming terraform-provider-aws v5.33.0, see https://github.com/hashicorp/terraform-provider-aws/pull/35037

Expected Behavior

Module should allow setting cluster's access_config and adding associations via aws_eks_access_entry and aws_eks_access_policy_association.

Use Case

Preserving sanity by not having to deal with aws-auth ConfigMap.

Describe Ideal Solution

Ideally there should be a way for existing cluster/state to migrate from authentication_mode = "CONFIGMAP" to authentication_mode = "API"

Alternatives Considered

Not using this module.

Additional Context

No response