Enable fatal_deprecations configuration per OpenStack service

Introduced namespaced variables for all OpenStack services supporting
this setting as defined through oslo libraries. Default value is False
in each case. Gating commit checks now enable the fatal_deprecations
setting for each supporting service.

Closes Bug: 1428412
Change-Id: I5f41d3fdfa1cc876efc0c33c657c9dad18a8ba51

defaults/main.yml

@@ -19,6 +19,7 @@ is_metal: true
 ## Verbosity Options
 debug: False
 verbose: True
+nova_fatal_deprecations: False
 
 ## System info
 nova_system_user_name: nova

templates/nova.conf.j2

@@ -7,6 +7,7 @@
 # Logs / State
 debug = {{ debug }}
 verbose = {{ verbose }}
+fatal_deprecations = {{ nova_fatal_deprecations }}
 log_dir = /var/log/nova
 state_path = {{ nova_system_home_folder }}
 lock_path = /var/lock/nova