Ignore commented lines in pipeline code coverage

[ebeahan]

Interested if it's possible to remove comment lines for the code coverage scoring for ingest pipelines.

As an example, the coverage score (65.7% when submitting) of this ingest pipeline is pulled down significantly with all the comment lines counting as uncovered code.

[haetamoudi]

Empty lines are also currently marked as 'uncovered code'. It would make sense to ignore them too

[jsoriano]

We'll take a look, maybe this is a regression from #1915.

[jsoriano]

When generating the base coverage we can probably ignore empty lines and comments depending on the format.

We do this in:

• elastic-package/internal/testrunner/coverage.go

  Line 163 in de694d8

  lines, err := countReaderLines(f)

• elastic-package/internal/testrunner/coverage.go

  Line 203 in de694d8

  lines, err := countReaderLines(f)