CDK-Lib EKS Constructs - Private repo support for artifacts

### Describe the feature

Allow customers to specify private repositories for external artifacts referenced by AWS provided constructs. For example, the AWS Load Balancer Controller construct directly references the public GitHub repo for its Helm chart:

https://github.com/aws/aws-cdk/blob/main/packages/aws-cdk-lib/aws-eks/lib/alb-controller.ts#L273

### Use Case

Security sensitive customers have requirements for all software artifacts to be sourced from internal vetted repos, that may take additional measures to ensure artifacts are immutable, and that consumption from upstream is vetted through organization required security checks. They cannot have.a deployment trigger a system to pull artifacts directly from a source on the internet.

### Proposed Solution

Expose artifact URLs as configuration instead of hard coding them in construct libraries. Allow customers to override the artifact URL with a local URL or OCI compliant repository for supported artifacts, such as container images or Helm charts.

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.92

### Environment details (OS name and version, etc.)

Amazon Linux 2

Start with packages/aws-cdk-lib/aws-eks/lib/alb-controller.ts around line 273, where the AWS Load Balancer Controller Helm chart references its public GitHub repository. Trace how supported artifacts are configured in the EKS constructs and define the scope for private local or OCI-backed URLs; done means supported artifacts can be sourced without direct internet access.

Written by the indexing model from the issue text.