chore(*) simplify xDS route configurers

[jpeach]

Summary

Add Dynamic and Scoped (not implemented) route configurers to match
the static one. Refactor the higher level inbound and outbound route
configurers in terms of the static configurer.

Full changelog

N/A

Issues resolved

N/A

Documentation

N/A

Testing

• Unit tests
• E2E tests
• Manual testing on Universal
• Manual testing on Kubernetes

Backwards compatibility

• Add backport-to-stable label if the code is backwards compatible. Otherwise, list breaking changes.

[codecov-commenter]

Codecov Report

Merging #2361 (6b3537f) into master (84d04ca) will increase coverage by 0.43%.
The diff coverage is 95.91%.

@@            Coverage Diff             @@
##           master    #2361      +/-   ##
==========================================
+ Coverage   52.10%   52.53%   +0.43%     
==========================================
  Files         874      878       +4     
  Lines       47797    47848      +51     
==========================================
+ Hits        24903    25137     +234     
+ Misses      20870    20665     -205     
- Partials     2024     2046      +22     

Impacted Files	Coverage Δ
...kg/xds/envoy/listeners/v3/http_route_configurer.go	92.00% <92.00%> (ø)
pkg/xds/envoy/listeners/configurers.go	96.40% <100.00%> (+0.13%)	⬆️
...voy/listeners/v3/http_inbound_routes_configurer.go	100.00% <100.00%> (+12.50%)	⬆️
...voy/listeners/v3/http_outbound_route_configurer.go	100.00% <100.00%> (+13.33%)	⬆️
pkg/kds/client/sink.go	47.72% <0.00%> (-4.55%)	⬇️
pkg/core/runtime/component/component.go	81.13% <0.00%> (-3.78%)	⬇️
pkg/dns/vips_allocator.go	74.19% <0.00%> (-1.62%)	⬇️
...kg/plugins/resources/k8s/native/pkg/test/within.go	100.00% <0.00%> (ø)
api/internal/util/proto/proto.go	70.00% <0.00%> (ø)
... and 18 more

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