feat: Implement M3 design elevation & shadow effects

- Added global toggles in the Themes tab
- Light color & directional user ovverides
- Independent shadow overrides per/bar
- Refactored various components to sync the updated designs

quickshell/Widgets/DankCircularImage.qml

@@ -81,6 +81,8 @@ Rectangle {
         mipmap: true
         cache: true
         visible: false
+        sourceSize.width: Math.max(width * 2, 128)
+        sourceSize.height: Math.max(height * 2, 128)
         source: !root.shouldProbe ? root.imageSource : ""
     }