In practice, Application Insights can take up to 3 minutes before something sent to it is available via KQL.
This PR logs a start and stop marker such that the integration tests only search for logs during the integration tests. This reduces the complexity when using the integration tests during the development process.
Note: this migrated the new functionality from #356 into the latest integration test tools.
Adds the following:
1. Serializes a workset to disk during setup.
2. Upon deserializing a RebootContext, delete the file from disk (We support rebooting once and only once)
3. Check if a workset exists with a RebootContext
1. If True, continuing processing
2. if False, mark the tasks & node as "Done" with appropriate errors via:
1. send WorkerEvent::Done events for each of the tasks in the work set
2. send StateUpdateEvent::Done for the node
