feat(*): hijack application metrics

[lukidzi]

Summary

Currently, to expose applications metrics Prometheus needs to communicate using mtls to scrape metrics from the application. This PR introduce change that allows to get application metrics without mTLS.

Full changelog

• [Bootstrap request now return different model but CP support old one]
• [Implement concurrent scraping metrics in kuma-dp]
• [Implement generate and send configuration]

Issues resolved

Fix #3457

Documentation

• Link to the website documentation PR

Testing

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

Backwards compatibility

• Update UPGRADE.md with any steps users will need to take when upgrading.
• Add backport-to-stable label if the code follows our backporting policy

[codecov-commenter]

Codecov Report

Merging #4286 (0227c33) into master (709ef04) will decrease coverage by 0.05%.
The diff coverage is 39.07%.

@@            Coverage Diff             @@
##           master    #4286      +/-   ##
==========================================
- Coverage   55.68%   55.63%   -0.06%     
==========================================
  Files         935      935              
  Lines       56433    56629     +196     
==========================================
+ Hits        31427    31505      +78     
- Misses      22531    22639     +108     
- Partials     2475     2485      +10     

Impacted Files	Coverage Δ
app/kuma-dp/pkg/dataplane/envoy/envoy.go	79.34% <ø> (ø)
pkg/plugins/runtime/k8s/metadata/annotations.go	100.00% <ø> (ø)
...est/framework/deployments/testserver/deployment.go	0.00% <0.00%> (ø)
...est/framework/deployments/testserver/kubernetes.go	0.00% <0.00%> (ø)
test/framework/interface.go	0.00% <0.00%> (ø)
test/framework/k8s.go	0.00% <0.00%> (ø)
test/framework/setup.go	2.69% <0.00%> (-0.01%)	⬇️
app/kuma-dp/pkg/dataplane/metrics/server.go	38.09% <12.19%> (-19.80%)	⬇️
pkg/xds/bootstrap/handler.go	36.36% <23.33%> (-12.66%)	⬇️
api/mesh/v1alpha1/metrics.pb.go	41.32% <32.60%> (-3.05%)	⬇️
... and 15 more

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[jakubdyszkiewicz]

bunch of nits, but overall 👍