fw/Artifact: Allows adding directories as artifacts
fw/Artifact: Allows adding directories as artifacts

Adds a `is_dir` property to an `Artifact` to indicate that the
artifact represents a directory rather than an individual file.

setrofim/workload-automation,ARM-software/workload-automation,ARM-software/workload-automation,setrofim/workload-automation,setrofim/workload-automation,ARM-software/workload-automation,ARM-software/workload-automation,setrofim/workload-automation