misc: rearrange demo theme resources.

demo/Semi.Avalonia.Demo/App.axaml

@@ -7,8 +7,15 @@
         <!-- You can still reference in old way.  -->
         <!-- <StyleInclude Source="avares://Semi.Avalonia/Index.axaml" /> -->
         <semi:SemiTheme Locale="zh-CN" />
-        <semi:SemiPopupAnimations/>
+        <semi:SemiPopupAnimations />
         <StyleInclude Source="avares://Semi.Avalonia.DataGrid/Index.axaml" />
         <StyleInclude Source="avares://Semi.Avalonia.ColorPicker/Index.axaml" />
     </Application.Styles>
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceInclude Source="Themes/_index.axaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
 </Application>

demo/Semi.Avalonia.Demo/Pages/HighContrastDemo.axaml

@@ -11,15 +11,6 @@
     <Design.DataContext>
         <vm:HighContrastDemoViewModel />
     </Design.DataContext>
-    <UserControl.Resources>
-        <ResourceDictionary>
-            <ResourceDictionary.MergedDictionaries>
-                <ResourceInclude Source="../Themes/ToggleSwitch.axaml" />
-                <ResourceInclude Source="../Controls/ColorItemControl.axaml" />
-                <ResourceInclude Source="../Controls/ColorDetailControl.axaml" />
-            </ResourceDictionary.MergedDictionaries>
-        </ResourceDictionary>
-    </UserControl.Resources>
     <SplitView
         Name="splitView"
         CompactPaneLength="50"

demo/Semi.Avalonia.Demo/Pages/PaletteDemo.axaml

@@ -14,17 +14,6 @@
     <Design.DataContext>
         <viewModels:PaletteDemoViewModel />
     </Design.DataContext>
-    <UserControl.Resources>
-        <ResourceDictionary>
-            <ResourceDictionary.MergedDictionaries>
-                <ResourceInclude Source="../Themes/ToggleSwitch.axaml" />
-                <ResourceInclude Source="../Controls/ColorItemControl.axaml" />
-                <ResourceInclude Source="../Controls/ColorDetailControl.axaml" />
-                <ResourceInclude Source="../Controls/FunctionalColorGroupControl.axaml" />
-                <ResourceInclude Source="../Controls/ShadowGroupControl.axaml" />
-            </ResourceDictionary.MergedDictionaries>
-        </ResourceDictionary>
-    </UserControl.Resources>
     <SplitView
         Name="splitView"
         CompactPaneLength="50"

demo/Semi.Avalonia.Demo/Themes/_index.axaml

@@ -0,0 +1,10 @@
+<ResourceDictionary xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceInclude Source="ColorDetailControl.axaml" />
+        <ResourceInclude Source="ColorItemControl.axaml" />
+        <ResourceInclude Source="FunctionalColorGroupControl.axaml" />
+        <ResourceInclude Source="ShadowGroupControl.axaml" />
+        <ResourceInclude Source="TabMenu.axaml" />
+        <ResourceInclude Source="ToggleSwitch.axaml" />
+    </ResourceDictionary.MergedDictionaries>
+</ResourceDictionary>

demo/Semi.Avalonia.Demo/Views/MainView.axaml

@@ -11,14 +11,6 @@
     x:CompileBindings="True"
     x:DataType="views:MainViewModel"
     mc:Ignorable="d">
-    <UserControl.Resources>
-        <ResourceDictionary>
-            <ResourceDictionary.MergedDictionaries>
-                <ResourceInclude Source="../Themes/TabMenu.axaml" />
-                <ResourceInclude Source="../Themes/ToggleSwitch.axaml" />
-            </ResourceDictionary.MergedDictionaries>
-        </ResourceDictionary>
-    </UserControl.Resources>
     <Grid RowDefinitions="Auto, *">
         <Border
             Grid.Row="0"