[CmdPal] Introduce Small, Medium, and Large sizing options for Details (#43956)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
This PR introduces 3 new sizing options to the Details Panel in the
Extensions API.
- `Small` (Default)
- `Medium`
- `Large`
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## PR Checklist

- [x] Closes: #43251
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issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **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
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
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pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
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- [ ] **Documentation updated:** If checked, please file a pull request
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and link it here: #xxx

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or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

Here's how it looks like:
```csharp
new ListItem(new NoOpCommand())
{
    Title = "Details on ListItems (Medium)",
    Details = new Details()
    {
        Title = "This item has medium details size",
        Body = "Each of these items can have a `Body` formatted with **Markdown**",
        Size = ContentSize.Medium,
    },
},
```

### Moving Pictures


![DetailsSize](https://github.com/user-attachments/assets/ae11b767-ecba-4b39-bd81-3e77eec93ed0)


<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

src/modules/cmdpal/Microsoft.CmdPal.UI/Pages/ShellPage.xaml

@@ -26,6 +26,7 @@
                 EmptyValue="Collapsed"
                 NotEmptyValue="Visible" />
 
+            <cmdpalUI:DetailsSizeToGridLengthConverter x:Key="SizeToWidthConverter" />
             <cmdpalUI:MessageStateToSeverityConverter x:Key="MessageStateToSeverityConverter" />
 
             <cmdpalUI:DetailsDataTemplateSelector
@@ -370,7 +371,7 @@
             <Grid x:Name="ContentGrid" Grid.Row="1">
 
                 <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="3*" />
+                    <ColumnDefinition Width="{x:Bind ViewModel.Details.Size, Mode=OneWay, Converter={StaticResource SizeToWidthConverter}}" />
                     <ColumnDefinition x:Name="DetailsColumn" Width="Auto" />
                 </Grid.ColumnDefinitions>