* Path lock utility for coordination between robustness engine actions
Add a utility to ensure path-based synchronization between goroutines. If a path is locked, a subsequent Lock will block if the requested path is the same, or a child/parent (recursive), of the locked path.
This assists with coordination between asynchronous robustness engine actions that may rely on the underlying data directory remaining unchanged. For example:
- between gathering a filesystem fingerprint and taking a snapshot.
- when one WriteFilesAtDepth command has traversed into a directory that another goroutine has picked for deletion.
* Fix linter
