Add resource properties to stack-preview

Certain resource details may influence the final price of the
infrastructure being created by a stack (e.g. instance flavors), so this
adds resources properties to the output of stack-preview.

Implements: blueprint stack-preview-details
Change-Id: I6ea892dedfc96aeda8e8a21e67562820fd21c7bb
Merge "Add resource properties to stack-preview"