State.py: robustness improvement; in some rare cases, DC workflow may have non-exist but defined as possible transitions. this improvement can avoid these error crush workflow conversion.

patches/States.py: add addPossibleTransition which acts as an universal method for both types of workflow.

Workflow.py: fix a confusion between list/tuple of variable value to make _executeMetaTrasition work.

Workflow.py: fix in getInfo, variable guard hasn't been checked properly; add _getStatusOf which get the workflow history correctly, and it is used to replace getCurrentStatusDict which does the same thing after correction. history key now directly get from workflow reference.

erp5_core: rename script checkConsistency to Document_checkConsistency to avoid conflict in new workflow conversion.

Workflow.py: when workflow managed role list is not defined, return an empty tuple to variable_match instead of None.

erp5_core: change the validation_workflow's script id checkConsistency to Document_checkConsistency.