This is a follow up to commit 529c3ff06693d0a1aa13081acff92010fe855c50.
It adds a proper exception on missing deploy steps and provides a proper
deprecation for the compatibility code when trying to continue deploy
for a node in the DEPLOYING state.
Change-Id: I6dc176c12a913cb481164a90881bb1c3107b36eb
Story: #2006963
