1. Validate that the attributes of the substitution mappings node type can be
accessed in the service template by substituted node.
2.Validate that an attempt to access any attributes not belong to a specific
node type or substitution mappings results into an expected error.
This patch is related to bp: https://review.openstack.org/#/c/345492/
Co-Authored-By: Sahdev Zala <spzala@us.ibm.com>
Change-Id: I5f6cdcf7eb66f20ba9e524b73edd249d2c7b1e31