New Cool Features

• Added support for scroll-to-top by tapping the status bar on iOS devices.
• Use curveAnimation to define a custom curve animation for the modal transition
• Bug fixes releated to horizontal scroll, clamping physics and othes.

New customizable params

• Use duration to define the opening duration of the modal
• Change the top radius of the cupertino bottom sheet with topRadius
  Thanks to @bierbaumtim @troyanskiy @rodineijf for the contributions

Scroll improvements and bug fixes

• Support for closing a modal with a scroll view by dragging down fast.
• Fix assertion in CupertinoBottomSheet and BottomSheetRoute when using the CupetinoApp or WidgetsApp as root
• Fix assertion when scrollController isn't used by the builder