* Add magnification of CupertinoSliverNavigationBar large title

* Fix padding in maximum scale computation

* Apply magnification by using RenderBox

* Do not pass key to the superclass constructor

* Use `clampDouble` instead of `clamp` extension method

* Remove trailing whitespaces to make linter happy

* Name test variables more precisely

* Move transform computation to `performLayout` and implement `hitTestChildren`

* Address comments

* Address comments

* Address comments

* Update comment about scale

* Fix hit-testing

* Fix hit-testing again

* Make linter happy

* Implement magnifying without using LayoutBuilder

* Remove trailing spaces

* Add hit-testing of the large title

* Remove whitespaces

* Fix scale computation and some tests

* Fix remaining tests

* Refactor and fix comments

* Update comments