use new payload objects for *_INIT callbacks

Part of the work we did while rehoming the callback modules introduced
the notion of payload objects [1] to replace the unstructured kwargs
used today. When using payloads event sources need to use publish()
rather than notify() to trigger the callback(s) and pass along a payload
object (if needed).

This patch begins to move us onto the payload objects by updating
BEFORE_INIT and AFTER_INIT event types to use the payloads.

Also see Ie8311f28ebac6c1990a261cc6cfa130fac0cfc5f

Depends-On: I9194c7857f10392149159071cda8e080e93adc10

[1] https://github.com/openstack/neutron-lib/blob/master/doc/source/devref/callbacks.rst#event-payloads

Change-Id: I3bdd5a0f4e142d1b9a59e2c110b19012ada78695

vmware_nsx/plugins/nsx_v/plugin.py

@@ -303,7 +303,7 @@ class NsxVPluginV2(addr_pair_db.AllowedAddressPairsMixin,
         # Bind QoS notifications
         qos_driver.register(self)
 
-    def init_complete(self, resource, event, trigger, **kwargs):
+    def init_complete(self, resource, event, trigger, payload=None):
         with locking.LockManager.get_lock('plugin-init-complete'):
             if self.init_is_complete:
                 # Should be called only once per worker

vmware_nsx/services/trunk/nsx_v3/driver.py

@@ -200,9 +200,9 @@ class NsxV3TrunkDriver(base.DriverBase):
                    agent_type=None, can_trunk_bound_port=True)
 
     @registry.receives(trunk_consts.TRUNK_PLUGIN, [events.AFTER_INIT])
-    def register(self, resource, event, trigger, **kwargs):
+    def register(self, resource, event, trigger, payload=None):
         super(NsxV3TrunkDriver, self).register(
-            resource, event, trigger, **kwargs)
+            resource, event, trigger, payload=payload)
         self._handler = NsxV3TrunkHandler(self.plugin_driver)
         for event in (events.AFTER_CREATE, events.AFTER_DELETE):
             registry.subscribe(self._handler.trunk_event,