* Improve messaging when storage account isn't found.
* Add client for finding resources when you don't know it's resource group.
* Add function to find Storage Account resource group name.
* Use the storage account resource group, not the virtual machine's resource group when deleting VHDs.
* Add description of storage account ID for clarity.
* Improve VHD deletion test when storage account is in different resource group.
* Use common function for ID parsing of storage account.