When running config-download if the deployment name property was not set
on a deployment resource from a ResourceGroup, it will trigger the code
path to lookup the grandparent resource name.
This codepath can be very slow depending on the number of nodes in the
stack.
This patch adds a warning when this is happening so that it's clear that
the name property needs to be set on the deployment resource.
Change-Id: I2cf7acef0999e1c36d4baa8c793bdaa78bd441ad
8532a397de