test-cases for CZIcmd

[ptahmose]

Is your feature request related to a problem? Please describe.
There should be tests for CZIcmd - c.f. #20 (review)

Describe the solution you'd like
Runs of CZIcmd should be part of the CI/CD, and the results are to be checked for correctness.
The test-data used for those runs have to be made available "somehow".

Describe alternatives you've considered
N/A

Additional context
N/A