Add back X11 legacy WM_NAME encodings Closes #4924. Based on patches of the past, such as this work by James Cloos in July 2010: https://github.com/exg/rxvt-unicode/commit/d7d98751b7385416ad1694b5f1fde6c312ba20d5, as well as code comments in the Perl module X11::Protocol::WM (https://metacpan.org/pod/X11::Protocol::WM) and even the code to Xlib itself, which taught me that we should never have been using `XStoreName`, all it does is call `XChangeProperty`, hardcoded to `XA_STRING`! What can I say, when the task is old school, the sources are too 😂