Supporting integration namespaces suffix

[oren-zohar]

Motivation Following:

• https://github.com/elastic/cloudbeat/issues/2229

Cloudbeat currently hard-code the data stream namespace. We need to get the namespace config and update the data stream accordingly

Definition of done What needs to be completed at the end of this task

• [ ] Update cloudbeat's data stream according to the integration's config

Out of scope Any UI/Kibana related changes

Related tasks/epics

• https://github.com/elastic/security-team/issues/9558

[kfirpeled]

Hi @kubasobon thanks for handling this one

Will it work for both vulnerabilities and findings?

[kubasobon]

@kfirpeled I think so. Currently testing to confirm it works for CNVM as well.

[kubasobon]

@kfirpeled I checked, and it needed some extra code changes, but I have achieved the same result for CNVM. Tested, screenshots in the PR.

[kubasobon]

@oren-zohar Here are the results of me testing various namespace settings

agent_policy.namespace	package_policies[].namespace	data_stream.namespace result
default	default	default
default	""	default
default	test	test
test	default	default
test	""	test
test	test	test

Conclusions:

1. Package Policy namespace overrides Agent Policy namespace setting
2. If Package Policy namespace is left empty, it uses Agent Policy namespace's value