OrchestratorServiceModule.psm1 occasionally not getting runbooks

I've had an interesting issue where the executerunbook function I wrote occasionally doesn't return the runbook.

I can't manage to reproduce the issue reliably yet enough that I am able to fully diagnose the issue, so as a work around I have added a retry option to the script.. where it tries to get the runbook again.

This will slow you down if you type the runbook name in wrong, but that's tough, and your own fault. I've uploaded the new version here (OrchestratorServiceModule.psm1) A quick screenshot of the fix, which now throws a warning rather than a terminating error:

One other thing is I have added a parameter for the poll interval when executing runbooks, which will help with slow running jobs and stopping them returning excessive amounts of verbose logging.