[entity] add an official ``cw_etype`` property for entity This property holds the CWEtype id of the entity. This information was previously available through __regid__ but this is an ugly public API. So we have a new clean public API. The ``dc_type()`` method could not be used as it is translated. (closes #2793792)

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"""%(distname)s views/forms/actions/components for web ui"""