yams #109550 lazy i18nization of ValidationError [done]

ValidationError should not be internationalized on the yams side, as at this time we may miss information such as end-user language (in terms of cw, think to exception raised on the repository side while the web server use http negociated language).

done in0.36.0
load left0.000
closed by#23a10f049447 don't translate validation error right away, let one i18n them later by calling exception.tr(trfunc). Closes #109550