xdragon: refactor

After removing duplicate package "dragon-drop" moving xdragon
to X11 folder.

pkgs/top-level/aliases.nix

@@ -273,6 +273,7 @@ mapAliases ({
   dolphinEmuMaster = dolphin-emu-beta; # Added 2021-11-10
   dotnet-netcore = dotnet-runtime; # Added 2021-10-07
   double_conversion = throw "'double_conversion' has been renamed to/replaced by 'double-conversion'"; # Converted to throw 2022-02-22
+  dragon-drop = throw "'dragon-drop' has been removed in favor of 'xdragon'"; # Added 2022-04-10;
   draftsight = throw "draftsight has been removed, no longer available as freeware"; # Added 2020-08-14
   dvb_apps = throw "dvb_apps has been removed"; # Added 2020-11-03
   dwarf_fortress = throw "'dwarf_fortress' has been renamed to/replaced by 'dwarf-fortress'"; # Converted to throw 2022-02-22

pkgs/top-level/all-packages.nix

@@ -2982,8 +2982,6 @@ with pkgs;
 
   dpic = callPackage ../tools/graphics/dpic { };
 
-  dragon-drop = throw "'dragon-drop' has been renamed to/replaced by 'xdragon'"; # Converted to throw 2022-03-27;
-
   dstp = callPackage ../development/tools/dstp { };
 
   dsvpn = callPackage ../applications/networking/dsvpn { };
@@ -34066,7 +34064,7 @@ with pkgs;
 
   sift = callPackage ../tools/text/sift { };
 
-  xdragon = lowPrio (callPackage ../applications/misc/xdragon { });
+  xdragon = lowPrio (callPackage ../tools/X11/xdragon { });
 
   xlockmore = callPackage ../misc/screensavers/xlockmore { };