tests: fix flaky gateway conformance HTTPRouteListenerHostnameMatching test

[pmalek]

What this PR does / why we need it:

This fixes setting the incorrect status for Gateway API routes.

• It sets the section name in ParentReference when it was specified
• It adds unit tests for cases where section names are specified and where more than 1 gateway is matching the route's ParentRefs
• It prevents adding multiple parentRefs status for the same parent which was found in local debugging

The relevant conformance test was run multiple times in a loop locally to ensure the fix is in place.

Which issue this PR fixes:

Fixes: #3721

PR Readiness Checklist:

Complete these before marking the PR as ready to review:

• the CHANGELOG.md release notes have been updated to reflect any significant (and particularly user-facing) changes introduced by this PR

[codecov]

Codecov Report

Patch coverage: 95.0% and no project coverage change.

Comparison is base (e87a4b7) 73.5% compared to head (1688039) 73.5%.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3732   +/-   ##
=====================================
  Coverage   73.5%   73.5%           
=====================================
  Files        133     133           
  Lines      15843   15828   -15     
=====================================
- Hits       11651   11646    -5     
+ Misses      3431    3423    -8     
+ Partials     761     759    -2     

Impacted Files	Coverage Δ
internal/controllers/gateway/route_utils.go	81.2% <95.0%> (+<0.1%)	⬆️

... and 3 files with indirect coverage changes

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[mlavacca]

I know this has already been merged and I'm late, but I wonder how this missing field can produce failures in an inconsistent way in our conformance tests 🤔

[pmalek]

I know this has already been merged and I'm late, but I wonder how this missing field can produce failures in an inconsistent way in our conformance tests 🤔

Missing section name was one of the things fixed in this PR. The problem apart from this one was most likely due to inconsistent status processing and at times, creating 2 nearly equal parent statuses for a route, which caused the "expect 1 parent, got 2" error in test logs.

[mlavacca]

I know this has already been merged and I'm late, but I wonder how this missing field can produce failures in an inconsistent way in our conformance tests thinking

Missing section name was one of the things fixed in this PR. The problem apart from this one was most likely due to inconsistent status processing and at times, creating 2 nearly equal parent statuses for a route, which caused the "expect 1 parent, got 2" error in test logs.

Gotcha, thanks for the explanation 🙏