Workspaces and work dir in sidecar

[wneirynck]

When configuring a work dir on a step and running it in an oci container, this will probably not work correctly, since the workspace is taken from the project root and will be restored as such. The correct way to handle this would be to run the sidecar in the root, as it currently works, but start the job container in the step work dir (which must be a sub dir of the project root).