Function drop_shadow 

pub fn drop_shadow(
    child: impl IntoUiNode,
    offset: impl IntoVar<Point>,
    blur_radius: impl IntoVar<Length>,
    color: impl IntoVar<Rgba>,
) -> UiNode

P Drop-shadow effect for the widget.

The shadow is pixel accurate.

This property is a shorthand way of setting filter to Filter::new_drop_shadow using variable merging.