refactor: use plugin annotation types from kubernetes-configuration

[pmalek]

What this PR does / why we need it:

This PR uses functions that interact with objects' plugin annotations from Kong/kubernetes-configuration#144.

Some of those introduce the usage of iterators using the iter package to prevent unnecessary allocations.

Benchmarks

Old

goos: darwin
goarch: arm64
pkg: github.com/kong/kubernetes-ingress-controller/v3/internal/dataplane/kongstate
cpu: Apple M1 Max
BenchmarkGetPluginRelations
BenchmarkGetPluginRelations-10            243942              4448 ns/op            6912 B/op         64 allocs/op
PASS
ok      github.com/kong/kubernetes-ingress-controller/v3/internal/dataplane/kongstate   1.762s

New

goos: darwin
goarch: arm64
pkg: github.com/kong/kubernetes-ingress-controller/v3/internal/dataplane/kongstate
cpu: Apple M1 Max
BenchmarkGetPluginRelations
BenchmarkGetPluginRelations-10            319242              3810 ns/op            7888 B/op         43 allocs/op
PASS
ok      github.com/kong/kubernetes-ingress-controller/v3/internal/dataplane/kongstate   2.814s

[codecov]

Codecov Report

Attention: Patch coverage is 95.65217% with 1 line in your changes missing coverage. Please review.

Project coverage is 80.1%. Comparing base (030db71) to head (aa91d31).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/dataplane/kongstate/kongstate.go	88.8%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #6644     +/-   ##
=======================================
+ Coverage   72.2%   80.1%   +7.9%     
=======================================
  Files        202     201      -1     
  Lines      25817   23951   -1866     
=======================================
+ Hits       18643   19190    +547     
+ Misses      6159    3783   -2376     
+ Partials    1015     978     -37     

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