Add a dry run mode for testing changed implementations

[baumeister25]

Every run does changes to the environment in zenhub.
It would be good to have dry run that lists the changes to test new implementations on feature branches.
The dry-run mode should be able to read from zenhub and instead of executing the commands for changes just log the changes that would be executed.

A pipeline should support this on feature branches, by automaticly running in dry-run mode