feat(hpa): add support for custom annotations on hpa

[GyunCho]

What this PR does / why we need it:

This PR adds support for custom annotations on HPA.
Custom annotations on HPA can be useful because by using annotations field, we can set things like ArgoCD sync wave that controls the order of installations via ArgoCD. Related Argo CD Doc

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes #

Special notes for your reviewer:

Checklist

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• PR is based off the current tip of the main branch.
• Changes are documented under the "Unreleased" header in CHANGELOG.md
• New or modified sections of values.yaml are documented in the README.md
• Commits follow the Kong commit message guidelines

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