Fix SliverPinnedPersistentHeader, also not able to update stretchConfiguration and showOnScreenConfiguration (#112043)

Fix RenderEditable not able to update backgroundCursorColor when the user provides a new one (#112045)

Pass through backgroundCursorColor parameter

Fix an reorderable list animation issue:"Reversed ReorderableListView drop animation moves item one row higher than it should #110949" (#111027)

* Introduce tests for tristate checkboxes

* Initial

* Use tristate changes in engine

* Flutter_test matchers test update

* Comments, tests

* Update packages/flutter/lib/src/semantics/semantics.dart
Co-authored-by: Chris Bracken <chris@bracken.jp>

* Assert mutual exclusivity

* Assert valid state before updating state

* Update packages/flutter/lib/src/semantics/semantics.dart

Typo fix in comment
Co-authored-by: Loïc Sharma <737941+loic-sharma@users.noreply.github.com>
Co-authored-by: Chris Bracken <chris@bracken.jp>
Co-authored-by: Loïc Sharma <737941+loic-sharma@users.noreply.github.com>

* Honor mixed state

* Prepare for change to engine

* Unused vars

* Remove comments

* Skip test for now

* Comment for skip

* Compartmentalize changes

* Justification comments