GitHubAction: tests have unnecessary output

[de-jcup]

Situation

Following tests provide unnecessary output:

• configuration-builder.test
• shell-arg-sanitizer.test
• client-version-helper.test
• init-scan.test

The verbose output (for green tests) becomes problematic on CI/CD when it comes to failure tracing.

Wanted

A npm run test shall have at least output as possible.
The results progress shall be the only output.

Solution

The output shall only appear when a debug flag is enabled inside the relevant test.
To do this, we mock core.error, core.info or core.debug (depending what is used) and
introduce a debug flag inside the tests. When debug is enabled, the mock shall do an output.