Keep source[_section] None on the New template tests

   This feature (with values set) is covered on Dual organisation settings.
   Unify code into mixin for Chinese scenarios
   Update Payzen for the new API
   Remove duplication and fix up assert
   Implement Test for Parallel subscriptions

      Test 2 organisations rather them a single one with parallel Subscriptions
      Move more code into the Mixin, for reuse it.

   Instead relies on Templates for define source[_section] for subscription related simulation use Subscription Condition (Path-Like), and by consequence Subscription Request, settings as source[_section] on Packing Lists.

  This allow us define multi-organisation providers of services, to comply of world-wide deployments.

   As the model is use single Open Order, it isn't possible to use multiple
   organisations (one per region), so we rely on Subscription Request Information
   to describe the providers.

See merge request nexedi/slapos.core!274

  Changes on PaymentTransaction_updateStatus were added for debugging purpose it seems.

See also nexedi/slapos!875

See merge request nexedi/slapos.core!271

  It is required due the replacement of the ownership.

   Sometimes the instances where the data is commited, don't have the same user set as the tests.

   Remove useless duplication on the security test (just duplication)
   Remove and include test for Organisation

  Move access into assignment based security

   Open tickets have to be handled by Administrators, and not by the user, only suspended tickets or confirmed upgrade decisions should be displayed on the front page, as it is duty of the user respond them.

slapos_subscription_request: (Test) Verbose why the subscription request isn't ordered by the script.