Add horizontal scrollbars to dashboard panels

lib/ui/dashboard/dashboard_chart.dart

@@ -43,6 +43,21 @@ class DashboardChart extends StatefulWidget {
 class _DashboardChartState extends State<DashboardChart> {
   String? _selected;
   int _selectedIndex = 0;
+  late ScrollController _controller;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _controller = ScrollController();
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+
+    super.dispose();
+  }
 
   void _onSelectionChanged(charts.SelectionModel model) {
     if (widget.onDateSelected == null) {
@@ -139,9 +154,12 @@ class _DashboardChartState extends State<DashboardChart> {
           Divider(height: 1.0),
           LimitedBox(
             maxHeight: settings.enableComparison ? 122 : 102,
+            child: Scrollbar(
+              controller: _controller,
               child: ListView(
                 shrinkWrap: true,
                 scrollDirection: Axis.horizontal,
+                controller: _controller,
                 children: widget.data!.map((dataGroup) {
                   final int index = widget.data!.indexOf(dataGroup);
                   final bool isSelected = index == _selectedIndex;
@@ -217,6 +235,7 @@ class _DashboardChartState extends State<DashboardChart> {
                 }).toList(),
               ),
             ),
+          ),
           Divider(height: 1.0),
         ],
         SizedBox(