Fix: preserve requested order for subnets when using aws-load-balancer-subnets annotation

[nelsen129]

Issue

#3915

Description

#3925 previously attempted to fix the issue of the subnet ID and EIP allocation order not matching. It did this by removing sorting from the output of AWS DescribeSubnets. However, since DescribeSubnets doesn't guarantee an order, this change made the order go from being deterministically wrong to being completely non-deterministic.

Now, this is using a map and re-generating the slice at the end of the listSubnetsByNameOrIDs to ensure that the output list is in the same order as the input.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: nelsen129
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• ✅ login: nelsen129 / name: Patrick Nelsen (defc1c1)

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