feat: HTTPRoute extensionRef filter converted onto plugin

[mlavacca]

What this PR does / why we need it:

Which issue this PR fixes:

Fixes #4812

Special notes for your reviewer:

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

Attention: 40 lines in your changes are missing coverage. Please review.

Comparison is base (46929c1) 77.7% compared to head (b19b294) 77.5%.
Report is 9 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #4838     +/-   ##
=======================================
- Coverage   77.7%   77.5%   -0.2%     
=======================================
  Files        165     166      +1     
  Lines      18480   18633    +153     
=======================================
+ Hits       14359   14458     +99     
- Misses      3296    3335     +39     
- Partials     825     840     +15     

Files	Coverage Δ
...rnal/dataplane/parser/translators/httproute_atc.go	90.8% <25.0%> (-2.2%)	⬇️
internal/dataplane/parser/translate_httproute.go	75.0% <29.4%> (-2.7%)	⬇️
internal/dataplane/parser/translators/httproute.go	86.9% <54.7%> (-5.0%)	⬇️

... and 8 files with indirect coverage changes

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[programmer04]

Linter complains @mlavacca