feat(bar): floating center area for widgets

* Added a new floating area at the center of the bar
* Optional center widgets config, fixed spacing on the center widget
* Turning transparency on by default

komorebi-bar/src/main.rs

@@ -269,7 +269,7 @@ fn main() -> color_eyre::Result<()> {
 
     let viewport_builder = ViewportBuilder::default()
         .with_decorations(false)
-        .with_transparent(config.transparency_alpha.is_some())
+        .with_transparent(true)
         .with_taskbar(false);
 
     let native_options = eframe::NativeOptions {