Add trace-cmd to CI

This merge-request adds a CI step running coccinelle build and step with trace-cmd enabled. Trace-cmd requires CI to run in a dedicated VM (and not in a docker container): terraform is used to dynamically create and destroy the VM during the CI pipeline. Credentials for CloudStack are stored in Gitlab CI variables (see Settings→CI/CD→Variables): these variables are required to run the trace-cmd steps (so they have to be redefined in forks).

This merge-request also adds an option -batch_mode to run -testall without any confirmation at the end.