[Stack Monitoring] Add system tests

[klacabane]

Summary

Let's add system tests to the Stack Monitoring packages. This will provide validation of the mappings and exercise each system end-to-end against live data which will enable #4013.

Being able to run system tests for each data streams means that we have to produce the necessary documents in the testing environments. Datasets like elasticsearch.cluster_stats or elasticsearch.node are available out of the box and do not need any trigger, but for other like logs or elasticsearch.ml_job we'll need to do some work. We're currently solving this for elasticsearch logs by loading a container that sends appropriate requests to the service, we can follow the same approach for other datasets.

• elasticsearch package
• kibana package
• logstash package

AC

• every data streams in each SM packages have a system test defined
• the tests are running against 8.5.0 version of the components
• the tests are running against a service defined in _dev/deploy (elasticsearch example)

[klacabane]

Logs tests can be implemented but metrics are blocked by elastic/elastic-package#979