[feat: gw api] Add event handling for Rules CRD

[shraddhabang]

Description

1. Added event handlers for Rules CRD
2. Fixed few minor typos in logs
3. Added unit tests for all the utility functions

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 🌟

[zac-nixon]

Do you want to return the local object reference, or is it better to load the actual CRDs and then attach them to the route descriptor? The idea of this route descriptor is that it holds data needed to make a complete gateway object, so we would need to have the CRD content loaded for the model builder.

[shraddhabang]

I prefer to keep the local object reference refs here for eventhandling since we may not need to load and attach that crd to the route if its not impacting any gateway. I plan to load the actual CRDs and attach those to RouteRule when we load attached rules since its more connected to rule than routes. https://github.com/kubernetes-sigs/aws-load-balancer-controller/blob/main/pkg/gateway/routeutils/loader.go#L73

[shuqz]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: shraddhabang, shuqz

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