refactor(hm/gui): reorganize modules

This way we are not `import`ing stuff which is slow.

It also makes it easier to turn off the sway module.

modules/hm/gui/sway.nix

@@ -25,7 +25,8 @@ in
           menu = "${pkgs.fuzzel}/bin/fuzzel --terminal '${termCmd}'";
         in
         {
-          inherit modifier terminal menu;
+          modifier = "Mod 4";
+          inherit terminal menu;
           # Appearance
           bars = [ ]; # Waybar is started as a systemd service
           gaps = {