Bad namespaced class names from apex-node break test retry logic

[JonnyPower]

Describe the bug

When using sfp apextests:trigger to run tests in a namespaced org, the test retry logic fails due to apex class full names being provided by upstream @salesforce/apex-node library (forcedotcom/salesforcedx-apex#296)

Waiting for an upstream fix in 4.x is problematic, so opening issue to track work with a fix within dx@scale rather than waiting for upstream fix.

To Reproduce
Steps to reproduce the behavior:

1. Create a scratch org with a namespace
2. Create unit tests that will hit a timeout or lock exception (I'm replicating reliably on our ISV product, but could also replicate with contention on org custom settings I suspect)
3. Run unit tests
4. apextests:trigger will run async then report failures and queue failed classes for a retry
5. class names are invalid (NS.NS__Foo instead of NS.Foo)

Expected behavior
A clear and concise description of what you expected to happen.

1. Should be able to retry test failures in namespaced test classes

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
Add any other context about the problem here.

• There is an open issue with upstream project, with a PR - the contributor has no signed the CLA. Class names returned for a namespaced package are in the format of namespace__classname. They should be namespace.classname forcedotcom/salesforcedx-apex#296 and Fixing Namespace for Async Tests forcedotcom/salesforcedx-apex#297
• From discussion with Azlam, preference is to fix now rather than waiting for 4.x upstream change due to complications introduced by Salesforce in the 4.x packages

[JonnyPower]

@azlam-abdulsalam can you assign to me? created this for branch issue reference

[azlam-abdulsalam]

Thanks for the detailed bug report @JonnyPower