https://docs.microsoft.com/en-us/windows/desktop/dataxchg/using-the-clipboard
discusses the techniques to monitor clipboard contents on Windows, and
recommends Clipboard Format Listener for Vista+.

https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-setclipboardviewer
further mentions that using the current "Clipboard Viewer Window" approach,
"The clipboard viewer chain can be broken by an application that fails to
handle the clipboard chain messages properly".

This change reimplements our listener to use recommended way; this
should make our clipboard handling more robust, avoiding the need to
handle the chain with other applications' windows.

Change-Id: Ib33b27a57d7a6af2ab7e3e59d030aa55329694f9
Reviewed-on: https://gerrit.libreoffice.org/62909Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>