ERP5Type.patches.DCWorkflow: Balance _push and _pop.

Otherwise fmt_data lookups becomes slower on each iteration.
Also, reword patch comments to be still descriptive when moved a bit
further from involved code.
ERP5Type.patches.DCWorkflow: Patch DCWorkflowDefinition.listObjectActions .

No change yet, just to have verbatim code for easier comparison.
ERP5Type.patched.DCWorkflow: Factorise consecutive tests.
ERP5Type.patched.DCWorkflow: Make transition id available.

Finally removes the need to hardcode transition id when it's the same as
current transition (which should be the case in the overwhelming majority
of transitions).