fix: Set AppWindow.Title to DisplayName

[lukeblevins]

Fixes: #208

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

Context:
On Windows targets, AppWindow currently lacks a default value for its Title property.

In our task for generating window icon, we form the code to retrieve an AppWindow from the XAML Window, using it to conveniently set the generated ico file.

What is the new behavior?

Upon retrieval of AppWindow, set AppWindow.Title to be the app's DisplayName. This value is obtained from the XAML Window instance which has a pre-defined Title property. (defaulting to DisplayName)

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Docs have been added/updated which fit documentation template. (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Wasm UI Tests are not showing unexpected any differences. Validate PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Updated the Release Notes
• Associated with an issue (GitHub or internal)

Other information

Internal Issue (If applicable):

[pictos]

This code doesn't work, from the top of my head, this looks like a Microsoft.Maui.Essentials call, so it will work just if we add a reference to that package, with I believe we don't want