Add support for customizable Plasma themes and configurations

- Introduced plasmaTheme variable in plasma.nix to allow selection between "desktop" and "laptop" themes.
- Created common theme configurations in common.nix, including keyboard shortcuts and application settings.
- Implemented desktop-specific configurations in desktop.nix, including panel layout, power management settings, and workspace appearance.
- Added laptop-specific configurations in laptop.nix, focusing on power-saving features and panel arrangements.
- Enhanced system monitoring widgets and battery management settings for both themes.

plasma/plasma.nix

@@ -9,6 +9,8 @@ let
       cp $src $out
     '';
   };
+
+  plasmaTheme = "desktop"; #Possible values are "laptop" or "desktop"
 in
 {
   imports =
@@ -17,6 +19,11 @@ in
     ../modules/stylix
   ];
 
+    # Pass the variable to home-manager
+  home-manager.extraSpecialArgs = {
+    inherit plasmaTheme;
+  };
+
   home-manager.sharedModules = [
     ./home.nix
   ];
@@ -84,7 +91,7 @@ in
       kdePackages.kdialog
       kdePackages.yakuake   #Drop down Terminal
       kdePackages.bluez-qt    #Bluetooth management for KDE Plasma
+      kdePackages.kconfig     #To Get infos about the current config, such as themes
     ];
   };
-
 }