Move file metrics to dataset endpoint

[vjsamuel]

Breaking change

What does this PR do?

The filemetrics are on the stats endpoint. It ideally is supposed to be on /dataset similar to metricbeat. This PR moves them to the right endpoint

Why is it important?

We use stats endpoint to collect metrics. These file metrics make the endpoint to verbose.

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.

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[elasticmachine]

Pinging @elastic/integrations (Team:Integrations)

[elasticmachine]

💚 Build Succeeded

Expand to view the summary

Build stats

• Build Cause: [urso commented: jenkins run the tests please]

• Start Time: 2020-07-21T21:29:37.479+0000

• Duration: 55 min 41 sec

Test stats 🧪

Test	Results
Failed	0
Passed	5508
Skipped	828
Total	6336

[urso]

This might be a breaking change.

@ycombinator Any idea if this namespace is used by monitoring?

[ycombinator]

No, Filebeat harvester files are currently not indexed in the Filebeat monitoring indices. So they are not used by monitoring.

[urso]

jenkins run the tests please