[Laucher] Added border on W10

[mantaionut]

Summary of the Pull Request

Added a border on W10 since only W11 had it.
Screenshots of the new look in W10.

PR Checklist

• Closes: [PowerToys Run] The background is not obvious #36391
• Communication: I've discussed this with core contributors already. If 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 for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

ResizeMode="NoResize" removes the border which on W11 was added back by enabling round corners

 
if (OSVersionHelper.IsWindows11())
{
   WindowInteropHelper(GetWindow(this)).EnsureHandle(); 
   DWMWINDOWATTRIBUTE attribute = DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE; 
   DWM_WINDOW_CORNER_PREFERENCE preference = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUND;  
   DwmSetWindowAttribute(hWnd, attribute, ref preference, sizeof(uint)); 
}  

Added a gray border on W10.

Validation Steps Performed

Tested On W10 and W11 on dark,light and all high contrast modes.

[jaimecbernardo]

This is best reviewed hiding whitespace chances in the diff. Main reason is that diff is showing badly the identation changes in the XAML file from adding the Border tag.

[davidegiacometti]

Working great! Thanks for the quick fix!
I left a minor suggestion: dynamic resource will play well with high contrast themes and also support color change without restarting the app.

[jaimecbernardo]

LGTM! Thank you