feat(eks-v2-alpha): use L1 CfnCluster to replace custom resource for EKS Cluster (#32400)

### Reason for this change

Get rid of the custom resource to provision EKS cluster by using L1 CfnCluster.

### Description of changes

Replace custom resource with native L1 CfnCluster

### Description of how you validated changes
unit tests and integration tests

### Checklist
- [ ] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: xazhao