Worklist.py: causality state getter returns an empty string instead of None when it is not definded.

ERP5TypeTestCase.py: install erp5_workflow template after finish erp5_base installation to not crash SQL initiation.

ERP5TypeTestCase.py: move dynamicalWorkflowConvertion to the end of Site creation, so the speed grains a great improvement.

Merge branch 'erp5_workflow_converted' of https://lab.nexedi.cn/Wenjie/erp5_workflow into erp5_workflow_converted

erp5_workflow: rename getRoleList to getManagedRoleList in interaction view and script PermissionRoles_asCellRange.

WorkflowTool.py: when convert interactions, the interaction contained script can only be script, it is no necessary to consider these script could be another interaction.

Using an instance of the class from the script create a huge memory leak
in zope which does not happen when instanciating class from the code.
The issue seems to come from the use by the matribox as simple test cases
of instanciation from script do not reproduce the memory leak