feat: Implement BackendUtilization LB OutOfBand reporting

[jukie]

What this PR does / why we need it:

Implementation for #9400 plus docs and e2e

Which issue(s) this PR fixes:

Fixes #9401

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[jukie]

Bump was needed to include the OrcaOobReportingConfig API field

[jukie]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. More of your lovely PRs please.

Reviewed commit: d90b0c865d

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[codecov]

Codecov Report

❌ Patch coverage is 90.47619% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.81%. Comparing base (1912d0e) to head (8945095).

Files with missing lines	Patch %	Lines
internal/gatewayapi/clustersettings.go	80.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9593      +/-   ##
==========================================
+ Coverage   75.80%   75.81%   +0.01%     
==========================================
  Files         258      258              
  Lines       42795    42816      +21     
==========================================
+ Hits        32440    32461      +21     
  Misses       8176     8176              
  Partials     2179     2179              

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[jukie]

CC @zhaohuabing #9400 (comment)

@zhaohuabing I ended up reverting this back to *int32. We only use it in one other place currently vs int32 for 8 other port fields and it breaks the kubebuilder bounds setup.

Let's continue here on whether to use PortNumber instead.