astakos: Update stress test code
astakos: Lock chain for projects, user for syncing
Lock project's chain for every operation affecting either a project oran application. Subsequently, lock user when needing to sync or to issuecommission to update pending_app quota.
In views, replace locking qh_add_pending_app with check_pending_app_quota,...
astakos: remove astakos.im.api module
Replace all AstakosCallpoint references
astakos: WIP move all api calls under ``/astakos/api``
Refs: #3340
Move transaction.py to snf_django package
Update stress test to use the new transaction decorator
Update projects stress test
Automate the stress test for projects
Testing scripts for astakos projects