Bring Shadow to IRoundedCorners views

[ederbond]

Description

It would be nice to have bindable properties like:
ShadowColor
ShadowOffset
ShadowOpacity
ShadowRadius

to allow the developer to control the Shadow on elements like Frame, StackLayout, Grid and etc.
Specially it should draw the shadow consistently on both iOS and Android
and works well with rounded corners elements.

[ederbond]

It would allow me to easly create a beaudifull bottom drawer like this:

Note the rounded corner on the TopRight and TopLeft of the drawer and also the subtle rounded shadow.

[ederbond]

#1754

[jfversluis]

This will not happen anymore for Xamarin.Forms. If this is still important to you, make sure to check the .NET MAUI repo and see if it's already on the roadmap or open an issue with a detailed feature request. Thanks!