expose cloud service client from scheduler package


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I'm not sure that's a good idea. When we first exposed this functionality in the .NET SDK, we had lots of bug reports because people thought it was generic for any cloud service, and started using it in ways that didn't work. Since this is a special one-off for scheduler, keeping it slightly hidden might be a good idea.

If we do expose it through azure.js, it should not be named `createCloudServiceManagementClient` but something like `createSchedulerCloudServiceManagementClient` maybe to avoid the confusion?