[8.15](backport #41868) auditbeat: split system process module

[mergify]

This splits the common module parts and the gosysinfo backend. Needed for an upcoming PR which adds a quark backend, so I'm splitting this earlier to make review easier.

Only functional change for this PR is adding two missing bucket.Close() calls in New().

Checklist

• My code follows the style guidelines of this project
  - [ ] I have commented my code, particularly in hard-to-understand areas
  - [ ] I have made corresponding changes to the documentation
  - [ ] I have made corresponding change to the default configuration files
  - [ ] I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

  ---

  This is an automatic backport of pull request auditbeat: split system process module #41868 done by Mergify.

[mergify]

Cherry-pick of 5a85598 has failed:

On branch mergify/bp/8.15/pr-41868
Your branch is up to date with 'origin/8.15'.

You are currently cherry-picking commit 5a85598f4e.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   CHANGELOG.next.asciidoc
	new file:   x-pack/auditbeat/module/system/process/gosysinfo_provider.go
	modified:   x-pack/auditbeat/module/system/process/process_test.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   x-pack/auditbeat/module/system/process/process.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[elasticmachine]

Pinging @elastic/sec-linux-platform (Team:Security-Linux Platform)