feature(web): Added full-screen button and volume slider (#50)

## Pull Request Description

Adds the full screen toggle to web and the volume slider.
fix: small fixes for desktop padding
fix: only reload widgets when the content has changed

## Issue Being Fixed

Issue Number: #28

---------

Co-authored-by: PartyDonut <PartyDonut@users.noreply.github.com>

lib/widgets/shared/full_screen_button.dart

@@ -0,0 +1,44 @@
+import 'dart:developer';
+
+import 'package:flutter/material.dart';
+
+import 'package:ficonsax/ficonsax.dart';
+import 'package:window_manager/window_manager.dart';
+
+class FullScreenButton extends StatefulWidget {
+  const FullScreenButton({super.key});
+
+  @override
+  State<FullScreenButton> createState() => _FullScreenButtonState();
+}
+
+class _FullScreenButtonState extends State<FullScreenButton> {
+  bool isFullScreen = false;
+
+  @override
+  void initState() {
+    super.initState();
+    Future.microtask(checkFullScreen);
+  }
+
+  void checkFullScreen() async {
+    final fullScreen = await windowManager.isFullScreen();
+    setState(() {
+      isFullScreen = fullScreen;
+    });
+    log(isFullScreen.toString());
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return IconButton(
+      onPressed: () async {
+        await windowManager.setFullScreen(!isFullScreen);
+        checkFullScreen();
+      },
+      icon: Icon(
+        isFullScreen ? IconsaxOutline.close_square : IconsaxOutline.maximize_4,
+      ),
+    );
+  }
+}