Problem: Users don't know what keys/values to enter for template and VM details.
Root Cause: The feature does not exist that can list possible details and options.
Solution: Based on the possible VM and template details handled by the
codebase, those details were refactored and a list API is introduced
that can return users those details along with possible values. When
users add details now, they will be presented with a list of key details
and their possible options if any.
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>