Add Access Entry support

[matthewgreenwaldagility]

This is a copy of a public pull request

This so that we can vendor this provider temporarily while we wait for the maintainers to resolve this pull request on the public repo.

Steps to reproduce locally:

git remote add upstream https://github.com/kubernetes-sigs/cluster-api-provider-aws.git
git fetch upstream
git fetch upstream pull/5583/head:pr-5583
git checkout -b cherry-pick-d6be19f
git cherry-pick d6be19f9177115a3b7da9e4a016646b9dbdcc8b3

What type of PR is this?
/kind feature

What this PR does / why we need it:

Adds support for configuring access entries, which is now the preferred way to manage IAM access to EKS clusters.

Which issue(s) this PR fixes (optional, in fixes #(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes kubernetes-sigs#4854

Special notes for your reviewer:
Depends on kubernetes-sigs#5578, and so includes a bunch of commits from that PR. I can hold this PR and rebase once that's merged if it makes it easier to review this, but wanted to open for visibility ASAP.

Checklist:

squashed commits
includes documentation
includes emoji in title
adds unit tests
adds or updates e2e tests

Release note:

Add support for configuring cluster IAM permissions via Access Entries