refactor(mobile): app settings (#7749)

* refactor(mobile): app settings

* Font size

* refactor(mobile): backup settings ui (#7771)

* refactor: SettingsButtonListTile

* refactor: Backup settings to App settings

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>

* fix: invalidate appsettingsprovider on timeline setting change

* styling

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>
Co-authored-by: Alex Tran <alex.tran1502@gmail.com>

mobile/lib/modules/settings/ui/settings_sub_page_scaffold.dart

@@ -0,0 +1,30 @@
+import 'package:flutter/material.dart';
+
+class SettingsSubPageScaffold extends StatelessWidget {
+  final List<Widget> settings;
+  final bool showDivider;
+
+  const SettingsSubPageScaffold({
+    super.key,
+    required this.settings,
+    this.showDivider = false,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return ListView.separated(
+      padding: const EdgeInsets.symmetric(vertical: 20),
+      itemCount: settings.length,
+      itemBuilder: (ctx, index) => settings[index],
+      separatorBuilder: (context, index) => showDivider
+          ? const Column(
+              children: [
+                SizedBox(height: 5),
+                Divider(height: 10, indent: 15, endIndent: 15),
+                SizedBox(height: 15),
+              ],
+            )
+          : const SizedBox(height: 10),
+    );
+  }
+}