Add proxy shell execution
What does this MR do?
Proxies shell execution via helper binary.
Why was this MR needed?
This doesn't achieve much at the moment, but can later be used for better process control and local masking.
What's the best way to test this MR?
This is all behind a config option, so the pipeline should pass successfully with it disabled.
Pipeline run https://gitlab.com/gitlab-org/gitlab-runner/-/pipelines/1702734684 had the setting enabled for everything but the Kubernetes executor to test it as part of every integration test.
We cannot yet test this in Kubernetes, because the helper changes are not reflected there until we push the helper image
What are the relevant issue numbers?
Edited by Arran Walker