Add clipBehavior to widgets with clipRect (#55977)

* Add clipBehavior to RenderFlex

* Add clipBehavior to FittedBox

* Add clipBehavior to Flex and FittedBox

* Add clipBehavior to UnconstrainedBox

* Add clipBehavior to Stack and Wrap

* Add clipBehavior to TextEditable

* Add clipBehavior to ListWheelScrollView

* Add clipBehavior to SingleChildScrollView

* Add clipBehavior to RenderViewportBase's widgets

Those widgets are NestedScrollView and ShrinkWrappingViewport.

* Fix tests

* Remove enum Overflow and fix typo

* Remove clipToSize

* Analyze fix

* Remove Mixin and other small fixes

* Fix tests and respect Stack's default clipBehavior

* Add Overflow back to make it non-breaking

* Restore clipBehavior to make it non-breaking

* Small fixes

* Fix rebase

dev/integration_tests/flutter_gallery/lib/demo/pesto_demo.dart

@@ -224,7 +224,7 @@ class _PestoLogoState extends State<PestoLogo> {
         child: SizedBox(
           width: kLogoWidth,
           child: Stack(
-            overflow: Overflow.visible,
+            clipBehavior: Clip.none,
             children: <Widget>[
               Positioned.fromRect(
                 rect: _imageRectTween.lerp(widget.t),