refactor: Allow automode controllers to customize the gateway controller

[zac-nixon]

Issue

Description

Key changes:

Makes the Gateway stack deployer and tracking provider injectable instead of constructing them internally.
Adds reconcile success/error callbacks for Gateway API controllers.
Makes Gateway controller setup more reusable between ALB and NLB implementations.
Fixes Gateway API CRD detection to require ReferenceGrant.
Removes the no-longer-needed v1beta1 Gateway API scheme registration.

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 🌟

[codecov-commenter]

Codecov Report

❌ Patch coverage is 21.62162% with 29 lines in your changes missing coverage. Please review.
✅ Project coverage is 57.48%. Comparing base (057c70f) to head (637849d).
⚠️ Report is 31 commits behind head on main.

Files with missing lines	Patch %	Lines
controllers/gateway/gateway_controller.go	0.00%	10 Missing ⚠️
...s/gateway/listenerrule_configuration_controller.go	0.00%	5 Missing ⚠️
...s/gateway/loadbalancer_configuration_controller.go	0.00%	5 Missing ⚠️
...rs/gateway/targetgroup_configuration_controller.go	0.00%	5 Missing ⚠️
controllers/gateway/gateway_class_controller.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4887      +/-   ##
==========================================
- Coverage   57.49%   57.48%   -0.01%     
==========================================
  Files         396      397       +1     
  Lines       31621    31708      +87     
==========================================
+ Hits        18179    18227      +48     
- Misses      12384    12422      +38     
- Partials     1058     1059       +1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[kubernetes-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: wweiwei-li, zac-nixon

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [wweiwei-li,zac-nixon]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment