feat(session-select): added XFCE support

Signed-off-by: Boris Yumankulov <boria138@altlinux.org>

usr/bin/portproton-session-select

@@ -87,6 +87,8 @@ case "$session" in
         [[ "$KDE6" != "true" ]] && session_launcher="plasmawayland"
       elif [[ "$de_normalized" == *hyprland* ]]; then
         session_launcher="hyprland"
+      elif [[ "$de_normalized" == *xfce* ]]; then
+        session_launcher="xfce-wayland"
       fi
     else
       if [[ "$de_normalized" == *gnome* ]]; then
@@ -96,6 +98,8 @@ case "$session" in
         [[ "$KDE6" != "true" ]] && session_launcher="plasma"
       elif [[ "$de_normalized" == *mate* ]]; then
         session_launcher="mate"
+      elif [[ "$de_normalized" == *xfce* ]]; then
+        session_launcher="xfce"
       fi
     fi
     create_sentinel=1