This patch fixes the interaction of Senlin with the database.
The standard model_query (joinload_all('*')) has been removed
in favor of using more distinctive join statements.
Additionally this patch removes the DB calls that were baked into the
to_dict() method for the Senlin objects and instead retrieves that
data with joins/single database calls. This allows cluster action
show to actually return within an appropriate amount of time.
This patch improves performance all around with considerably less CPU
usage.
Closes-Bug: #1817604
Change-Id: Ie5c1fca080c82833941edc130568e76701ce394c
9f49cfdfb2