Query methods on instance store should be defined by interface IOrchestrationServiceInstanceStore

Right now it is not possible to use Query methods (like QueryOrchestrationStatesAsync) on instance store service.

Right now we are required in many solutions to enlist states of running instances. Because TaskHubClient and TaskHubWorker do not provide such methods and there is not access to instance store service inside of named classes, we cannot query for instances.

This method is implemented in AzureTableInstanceStore, but it cannot be accessed from projects, which do have reference ServiceBus assembly directly.

Thanks