+ improve TALES on transition guard role list

setting state category on workflow was overriding other catogories
(in particular the before/after script newly created)

and before_script_id to before_script

Too many method_id were changed to use getTriggerMethodId
It should not be used on activities...

they were originally named before_script and after_script and some
old names remained

+ rename field my_destination_title to my_destination to avoid using magic

missing "my_"

dynamic_class_generation_interaction_workflow

need to be investigated

this property seems not to be used on ERP5 in old DC workflow

- change guard-related description to be more clear and consistent
- remove expression from Transition view
- show right guard properties (were renamed)

fix Workflow creation/removal