Add data field to action DB model for policy_check

This patch added a data field to action DB model. This field is
used to store result data that generated during policy_check and
action execution. Based on this, policy_data parameter is not
needed anymore when invoking attach/detach/pre_op/post_op methods
of policy and all action methods.

This patch also recorded the id of nodes which was deleted or
created during action progress. This id list will be persisted
into DB as action data and then consumed by policies whose check
target is 'AFTER'.

Change-Id: I88cb033974b57acda1678039a8362bdbee5bf7a4

senlin/db/sqlalchemy/migrate_repo/versions/001_first_version.py

@@ -207,6 +207,7 @@ def upgrade(migrate_engine):
         sqlalchemy.Column('created_time', sqlalchemy.DateTime),
         sqlalchemy.Column('updated_time', sqlalchemy.DateTime),
         sqlalchemy.Column('deleted_time', sqlalchemy.DateTime),
+        sqlalchemy.Column('data', types.Dict),
         mysql_engine='InnoDB',
         mysql_charset='utf8'
     )

senlin/db/sqlalchemy/models.py

@@ -296,6 +296,7 @@ class Action(BASE, SenlinBase, SoftDelete):
     created_time = sqlalchemy.Column(sqlalchemy.DateTime)
     updated_time = sqlalchemy.Column(sqlalchemy.DateTime)
     deleted_time = sqlalchemy.Column(sqlalchemy.DateTime)
+    data = sqlalchemy.Column(types.Dict)
 
 
 class Event(BASE, SenlinBase, SoftDelete):