Revert "Load resources using Resource.load_all_from_stack()"

This reverts commit 570e69b7ab0ee16f29d66ab4157a582912ec6017.

We are seeing issues with missing heat data obtained from
the Heat CFN API in TripleO.

Change-Id: Ideea039e51ae7fb3350ee1f35706adce8847de64
Closes-bug: #1331720