Replace CupertinoSliverRefreshControl.onRefresh's then callback with whenCompleted callback, so when onRefresh completes with error the sliver refresh control retracts like when it completes with value.

* Re-enable const

This re-lands the Focus changes in #30040. Correctness changes in routes.dart, and removes the automatic requesting of focus on reparent when there is no current focus, which caused undesirable selections.

Addresses #11344, #1608, #13264, and #1678
Fixes #30084
Fixes #26704

Fix a bug where text selection handles were invisible in iOS

This reverts commit 4218c0bc.

Implements focus traversal for desktop platforms, including re-implementing the existing focus manager and focus tree.

This implements a Focus widget that can be put into a widget tree to allow input focus to be given to a particular part of a widget tree.

It incorporates with the existing FocusScope and FocusNode infrastructure, and has minimal breakage to the API, although FocusScope.reparentIfNeeded is removed, replaced by a call to FocusAttachment.reparent(), so this is a breaking change:

FocusScopeNodes must now be attached to the focus tree using FocusScopeNode.attach, which takes a context and an optional onKey callback, and returns a FocusAttachment that should be kept by the widget that hosts the FocusScopeNode. This is necessary because of the need to make sure that the focus tree reflects the widget hierarchy.

Callers that used to call FocusScope(context).reparentIfNeeded in their build method will call reparent  on a FocusAttachment instead, which they will obtain by calling FocusScopeNode.attach in their initState method. Widgets that own FocusNodes will need to call dispose on the focus node in their dispose method.

Addresses #11344, #1608, #13264, and #1678
Fixes #30084
Fixes #26704

initialDateTime should account for minuteInterval

Add golden tests for CupertinoDatePicker

-* Inserted an `IconTheme` widget under `CupertinoTheme` to provide a default icon color when using `CupertinoTheme`.
* Changed `CupertinoTheme` to a `StatelessWidget`, to match the implementation of `Theme`
* Changed the nesting order of `Theme`'s sub widgets, to let `Theme.iconTheme` take precedence, so that `Theme`'s behavior is kept as is.

Remove the additional top padding from CupertinoPageScaffold's MediaQuery when the navigation bar is opaque (as the padding was already consumed by the navigation bar).

Related Issue: #29136

* fix indentof statements in BlockFunctionBody

* fix indentof statements in BlockFunctionBody in tests

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

Breaks the moveBy call from drag and dragFrom into two separate calls and changes the default behavior of DragStartBehavior to DragStartBehavior.start (#26438)

* Breaking change which sets the default DragStartBehavior to DragStartBehavior.start and changes WidgetTester.drag and WidgetTester.dragFrom by breaking the moveBy function call into multiple pieces.

* Fix for nan pressure values and values outside min and max pressure ranges