feat(kuma-cp) automatically enable gzip content on gateways

[jpeach]

Summary

Always configure the compressor filter to enable gzip compression if
the client negotiates the relevant content types. This is a safe and
conservative default that can benefit many clients.

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 #3104 (3f585e0) into master (40f8aa3) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3104      +/-   ##
==========================================
+ Coverage   52.36%   52.38%   +0.01%     
==========================================
  Files         923      923              
  Lines       53491    53510      +19     
==========================================
+ Hits        28012    28029      +17     
- Misses      23245    23247       +2     
  Partials     2234     2234              

Impacted Files	Coverage Δ
.../plugins/runtime/gateway/filter_chain_generator.go	76.10% <100.00%> (+0.15%)	⬆️
...kg/xds/envoy/listeners/filter_chain_configurers.go	97.43% <100.00%> (+0.33%)	⬆️
pkg/insights/components.go	70.00% <0.00%> (-30.00%)	⬇️
pkg/events/eventbus.go	85.18% <0.00%> (-7.41%)	⬇️
pkg/plugins/runtime/gateway/route/sorter.go	61.53% <0.00%> (-5.13%)	⬇️
pkg/insights/resyncer.go	67.22% <0.00%> (-2.68%)	⬇️
pkg/mads/v1/client/client.go	41.25% <0.00%> (-2.50%)	⬇️
api/observability/v1/mads.pb.go	34.53% <0.00%> (-1.04%)	⬇️
pkg/xds/generator/direct_access_proxy_generator.go	83.90% <0.00%> (+1.14%)	⬆️
pkg/core/resources/manager/cache.go	88.31% <0.00%> (+5.19%)	⬆️
... and 4 more

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