now raise UnknownProperty, not KeyError

fix test broken by introduction of ViewSameEType action

kill register_appobject_class method, simplifying autoregistration. Update test accordingly (test which manually registers object should also properly call there __register__ method). Drop the disable-appobjects config file entry: no one used it since its introduction years ago.

backport stable branch and some vreg cleanups: * move initialization_completed from cwvreg to base VRegistry class allowing simplification of CWVregistry * cleanup initialization process: __registered__ is now called after initialization completed, by the relevant registry. * fix/remove deprecated tests

fix security issue #36564 (integrity error w/ RQLUniqueConstraint) by using a global lock serializing commit when some RQLUniqueConstraint is encountered.

errors on postcommit should never occurs, log it as critical