network_traffic: add config option to monitor processes

[efd6]

What does this PR do?

This adds a config option to turn on process monitoring. It is off by default, but made a non-hidden option to bring it forward in user attention.

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.
• I have verified that Kibana version constraints are current according to guidelines.

Author's Checklist

• Relevant enablement code in packetbeat
  • https://github.com/elastic/beats/blob/72cea9866370bc16f871716a75357de329ca1b74/packetbeat/config/config.go#L35
  • https://github.com/elastic/beats/blob/72cea9866370bc16f871716a75357de329ca1b74/packetbeat/procs/config.go#L22-L27
  • https://github.com/elastic/beats/blob/72cea9866370bc16f871716a75357de329ca1b74/packetbeat/procs/procs.go#L132-L140
• Unused cmd_linegrep code in packetbeat — does not alter behaviour wrt filtering processes, just rewrites names.
  • https://github.com/elastic/beats/blob/72cea9866370bc16f871716a75357de329ca1b74/packetbeat/procs/procs.go#L270-L277

How to test this PR locally

Related issues

Screenshots

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2022-06-01T22:36:25.461+0000

• Duration: 73 min 7 sec

Test stats 🧪

Test	Results
Failed	0
Passed	264
Skipped	0
Total	264

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

[elasticmachine]

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

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (0/0)	💚
Files	100.0% (0/0)	💚 3.538
Classes	100.0% (0/0)	💚 3.538
Methods	71.875% (46/64)	👎 -16.835
Lines	100.0% (0/0)	💚 10.279
Conditionals	100.0% (0/0)	💚