Create standard workflows and actions

 * Standard workflows are creating during sync_db.sh
 * Standard workflows include:
     - std.create_instance
     - std.delete_instance
     (list will be extended in future)
 * Standard actions:
     - std.wait_ssh (needed for std.create_instance)
 * Make it possible to see these workflows from any project (global scope)
 * Small changes in sqlalchemy api and workflows_service

Partially implements blueprint mistral-multitenancy

Change-Id: I8a8ace40949b2b711a292aac94d7e6354d1dff9c