* Make Cupertino page transition elevation animated too

* Rename and change physical model to a decorated box

* Tests

* Add a comment

* still need to handle null in the tween somewhere

* nits

* Tweens evaluate to the actual begin/end instances. Let them be non-null

* Rename no decoration to none

Remove intermediate animation listener

* Just realized the creation order is the other way around

* Works

* Revert previous partial solution

* Change pumpAndSettle to pump for gestures

* Moved stuff around yet

* Fix depedencies

* Add more dartdoc comments to packages

* Remove Cupertino dependency on material

* Removed mountain_view package and added page transition test

* Fix analyze warnings

* Remove commented code

* Partial solution. Still need to stop the animation on the previous page for modal

* Some review notes

* Move the cupertino back gesture controller’s lifecycle management back to its parent

* Reviews

* Add background color

* Directional curves, full screen transition

* Don’t perform the exit animation if the incoming page is a dialog

* It works!

* Test structures

* Add a bunch of more tests and fix the gallery

* One more comment

* Review notes

* final controller

* Use that sweet sweet `is!` keyword

* Play golf, because I’m bitter that there’s no nullable `as` or something in dart

* Remove a space

* Review notes

* Remove the last deprecated test

* Moved stuff around yet

* Fix depedencies

* Add more dartdoc comments to packages

* Remove Cupertino dependency on material

* Removed mountain_view package and added page transition test

* Fix analyze warnings

* Remove commented code

* Some review notes

* Move the cupertino back gesture controller’s lifecycle management back to its parent

* Reviews

* Add background color

* final controller

* Review notes