✨ feat: add support for controlplane egress mode

[richardcase]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Add support for specifying the mode for the control plane egress traffic. The default is to let AWS manage this. It can be changed to "customer routed" which gives greater control to the routing at the cost of you having to manage the routing.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

AI Usage:

None

Checklist:

• squashed commits
• includes documentation
• includes AI generated content
• includes emoji in title
• adds unit tests
• adds or updates e2e tests

Release note:

Add support for EKS control plane egress mode

[kubernetes-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign andidog for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[richardcase]

/test pull-cluster-api-provider-aws-e2e-blocking

[kubernetes-prow]

@richardcase: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-cluster-api-provider-aws-e2e-blocking	39871ac	link	true	/test pull-cluster-api-provider-aws-e2e-blocking
pull-cluster-api-provider-aws-test	39871ac	link	true	/test pull-cluster-api-provider-aws-test

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.