bugfix(report): metrics reporter: prevent error by ignoring folders for which Ca/Ce/I can't be calculated

[sverweij]

Description

• makes the metrics reporter ignore folders for which metrics couldn't be calculated.

Motivation and Context

If metrics were asked for folders for which I/Ca/Ce can't be calulated e.g. because they match the doNotFollow attribute (e.g. node_modules go typically in there) the metrics reporter borked with a cannot read xxx of yyy error. As it doesn't make sense to show
metrics for these folders they should've been left out in the first place - which is what this PR fixes.

How Has This Been Tested?

• green ci
• additional automated integration test

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Documentation only change
• Refactor (non-breaking change which fixes an issue without changing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• 📖

  • My change doesn't require a documentation update, or ...
  • it does and I have updated it

• ⚖️

  • The contribution will be subject to The MIT license, and I'm OK with that.
  • The contribution is my own original work.
  • I am ok with the stuff in CONTRIBUTING.md.