ux: width of quick launcher popup

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/Launcher.axaml

@@ -128,7 +128,7 @@
             Background="Transparent"
             IsVisible="{Binding QuickLauncher, Converter={x:Static ObjectConverters.IsNotNull}}"
             PointerPressed="OnCloseQuickLauncher">
-      <Border HorizontalAlignment="Center" VerticalAlignment="Center" Effect="drop-shadow(0 0 12 #A0000000)">
+      <Border Width="400" HorizontalAlignment="Center" VerticalAlignment="Center" Effect="drop-shadow(0 0 12 #A0000000)">
         <Border Background="{DynamicResource Brush.Popup}" CornerRadius="8">
           <ContentControl Margin="16,10,16,12" Content="{Binding QuickLauncher}">
             <ContentControl.DataTemplates>

src/Views/QuickLauncher.axaml

@@ -49,7 +49,6 @@
 
     <ListBox Grid.Row="2"
              x:Name="PageListBox"
-             Width="300"
              MaxHeight="250"
              Margin="4,0"
              BorderThickness="0"
@@ -120,7 +119,6 @@
 
     <ListBox Grid.Row="4"
              x:Name="RepoListBox"
-             Width="300"
              MaxHeight="300"
              Margin="4,0"
              BorderThickness="0"