refactor(makefile): reorganize docker build and push targets

[omerap12]

Issue

NONE

Description

When manually building the AWS Load Balancer Controller, I noticed there wasn't a dedicated docker-build command for local testing and development. This PR adds structured build and push targets to improve the development workflow.

This change allows users to:

1. Build locally without pushing using any of the three methods
2. Push using the original ko-based workflow
3. Optionally use traditional docker or buildx for pushing

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: omerap12
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