xremap: add missing client variants (#498722)

      features = [ "hypr" ];

      descriptionSuffix = "Hyprland";

    };

    niri = {

      suffix = "-niri";

      features = [ "niri" ];

      descriptionSuffix = "Niri";

    };

    cosmic = {

      suffix = "-cosmic";

      features = [ "cosmic" ];

      descriptionSuffix = "Cosmic";

    };

    socket = {

      suffix = "";

      features = [ "socket" ];

      descriptionSuffix = "Socket client";

    };

  };

  variant = variants.${withVariant} or null;