Same as https://github.com/apache/datafusion/issues/16865 but for UDWF (`WindowUDFImpl`). - depends on https://github.com/apache/datafusion/issues/16865. That issue needs to be done first to define how it should be done. - this should update all `WindowUDFImpl` that today have explicit equals/hash implementations - can be located with a regex `WindowUDFImpl for((?!\n\}).|\n)* *fn equals`