allow to show browser console output in tests

[individual-it]

Description

I had a hard time debugging some CI issues, till I finally showed the output of the browser console.
This allows to set the env. variable DEBUG to true and then the browser console output will be shown in the test run.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Tests only (no source changes)
• Documentation only (no source changes)
• Maintenance (e.g. dependency updates or tooling)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation updated