* Allow configuring max request header size

This allows configuring the HTTP max request header size from the jetty
server.
By default it uses 8192, the same jetty default.

These fields in `stateMap` metadata are not used by `metadata-service-mapping.yaml` now and there is low possibility that they may be used in real case, but, they cost a lot to deserialize, so we remove them to improve performance

From what I've tested, the analyzer can process 250k ALS logs before trimming the fields and can process 420k ALS logs after trimming the fields

Perf: optimize Envoy ALS analyzer performance in high traffic load scenario (reduce ~1cpu in ~10k RPS) (#7182)

* OAL supports generating metrics from events

* Add new dashboard for event metrics

* Add some docs for event metrics

* Fix ALS K8SServiceRegistry didn't remove the correct entry

* Add changes
Co-authored-by: NZhenxu Ke <kezhenxu94@apache.org>

Add telemetry data about metrics in, metrics scraping and trace in metrics to zipkin receiver. (#6516)

Happy Chinese New Year !!

Add some defensive codes for NPE and bump up Kubernetes client version to expose exception stack trace (#6327)

* [maven-release-plugin] prepare release v8.4.0

* [maven-release-plugin] prepare for next development iteration

Fix that the dynamic configuration is deleted on the server side but does not take effect on the agent. (#6255)
Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>