[controller] UndoController: fix output method (closes: #1776091)
Fix buggy direct output in `UndoController.publish()`.
Raise now a ValidationError instead of malformed string
Changes:
* raise ValidationError when an error occured in undo
* use the new message mechanism based on _cwmsgid
If errors are not fatal, you have to change publish() method.
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.*/data/database/.*\.sqlite
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