[AP] Adding a single scrollviewer and fixing hidden tabstop (#43660)

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## Summary of the Pull Request

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## PR Checklist

- [x] Closes: #43655
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- [ ] **Communication:** I've discussed this with core contributors
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- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
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- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
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## Detailed Description of the Pull Request / Additional comments

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## Validation Steps Performed

src/modules/AdvancedPaste/AdvancedPaste/AdvancedPasteXAML/Pages/MainPage.xaml

@@ -299,7 +299,8 @@
                 </StackPanel>
             </controls:PromptBox.Footer>
         </controls:PromptBox>
-        <Grid Grid.Row="2" RowSpacing="4">
+        <ScrollViewer Grid.Row="2">
+            <Grid RowSpacing="4">
                 <Grid.RowDefinitions>
                     <RowDefinition Height="{x:Bind ViewModel.StandardPasteFormats.Count, Mode=OneWay, Converter={StaticResource standardPasteFormatsToHeightConverter}}" />
                     <RowDefinition Height="Auto" />
@@ -316,8 +317,8 @@
                     ItemContainerTransitions="{x:Null}"
                     ItemTemplateSelector="{StaticResource PasteFormatTemplateSelector}"
                     ItemsSource="{x:Bind ViewModel.StandardPasteFormats, Mode=OneWay}"
-                ScrollViewer.VerticalScrollBarVisibility="Visible"
+                    ScrollViewer.VerticalScrollBarVisibility="Disabled"
-                ScrollViewer.VerticalScrollMode="Auto"
+                    ScrollViewer.VerticalScrollMode="Disabled"
                     SelectionMode="None"
                     TabIndex="1" />
                 <Rectangle
@@ -336,10 +337,11 @@
                     ItemContainerTransitions="{x:Null}"
                     ItemTemplateSelector="{StaticResource PasteFormatTemplateSelector}"
                     ItemsSource="{x:Bind ViewModel.CustomActionPasteFormats, Mode=OneWay}"
-                ScrollViewer.VerticalScrollBarVisibility="Visible"
+                    ScrollViewer.VerticalScrollBarVisibility="Disabled"
-                ScrollViewer.VerticalScrollMode="Auto"
+                    ScrollViewer.VerticalScrollMode="Disabled"
                     SelectionMode="None"
                     TabIndex="2" />
             </Grid>
+        </ScrollViewer>
     </Grid>
 </Page>