[iptables] Set event.module and event.dataset

[marc-gr]

What does this PR do?

Sets event.module and event.dataset

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• If I'm introducing a new feature, I have modified the Kibana version constraint in my package's manifest.yml file to point to the latest Elastic stack release (e.g. ^7.13.0).

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)

[elasticmachine]

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Build stats

• Build Cause: Pull request #1266 updated

• Start Time: 2021-06-30T11:29:39.798+0000

• Duration: 11 min 10 sec

• Commit: 06b11ac

Test stats 🧪

Test	Results
Failed	0
Passed	26
Skipped	0
Total	26

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