x11-wm/kwinft: add new port

KWinFT (KWin Fast Track) is a robust, fast and versatile yet easy to
use composited window manager for the Wayland and X11 windowing
systems on Linux.

The KWinFT project is a reboot of KDE's KWin and intended to be used
as part of a KDE Plasma Desktop.

https://gitlab.com/kwinft/kwinft