[Feature request]Support Mica brush for Popup just like FluentWindow in v3.x #747
Description
Is your feature request related to a problem? Please describe
Just like the Flyout/Popup/Combbox.
WinUI's Flyout/Combbox is Mica backdrop nowaday.
Describe the solution you'd like
Popup like a borderless Window.
No idea now.
Describe alternatives you've considered
No response
Additional context
No response