Follow-up from #196972: How does hook_views_tabs() work?: Let's add the $sub_property_path of a validation violation to the errorElement() method of widgets, so they can be easily used when mapping them to elements. Probably, we can also default to 1:1 mapping between violated properties and elements.
Right, now those sub property path is already calculated and available via the undocumented $violation->arrayPropertyPath property.