Create wrapper for file save picker

[DeadlyEmbrace]

Description

Create a wrapper for the FileSavePicker.
Because I mostly plan to use it from a Desktop app it should provide a wrapper for setting the window handle to prevent an error. For this create a helper that can store the main window that will be the owner of the item. The TabWindow should inject itself into this helper.

See:

• Preview 4 - FolderPicker and FilePicker not working / App crashes microsoft/WindowsAppSDK#466 (comment)
• FileSavePicker Break in WinUI3 Desktop microsoft/WindowsAppSDK#909
• FileOpenPicker PickMultipleFilesAsync Break in WinUI3 Desktop microsoft/WindowsAppSDK#467

Tasks

• Implement