My yearly pass to fix spelling errors in the API dartdocs.

This removes the nullOk parameter from Focus.of, FocusTraversalOrder.of and FocusTraversalGroup.of, and creates maybeOf equivalents for each. The of methods now return non-nullable values, and the maybeOf equivalents return nullable values.

This removes the nullOk parameter from AnimatedList.of and SliverAnimatedList.of, and creates maybeOf equivalents for each. The of methods now return non-nullable values, and the maybeOf equivalents return nullable values.

This removes the nullOk parameter from Router.of, and createsRouter.maybeOf. Router.ofnow returns a non-nullable value, and the Router.maybeOf returns a nullable value.

This removes the nullOk parameter from Shortcuts.of, Actions.find and Actions.handler and created Shortcuts.maybeOf and Actions.maybeFind. Shortcuts.of and Actions.find now return non-nullable values, and the maybe versions return a nullable value. I didn't create a non-nullable version of Actions.handler, since it needs to be able to return null if an action is not enabled, but I did remove the nullOk parameter, effectively setting it to true permanently, since setting it to false doesn't make much sense if the function can still return null when the action is not enabled.

(Reland) Fixes a bug where keyboard capitalization behavior was reset by TextEditingController.clear.

Fixes a bug where selection handles sometimes showed on web.

Adds MediaQuery.maybeOf to replace calling MediaQuery.of(context, nullOk: true), and removes the nullOk parameter. Also changes MediaQuery.of to return a non-nullable value, and removes many instances of the ! operator, reducing the possible places where a null dereference could occur.

Just a docs-only improvement in EditableText and text input.

A new widget that chooses an item from a list based on text input. Just the core widget, with Material and Cupertino versions to come.

This reverts commit 95909c2a.

Fixes a bug where keyboard capitalization mode was exited when pressing clear.

Move service extension to correct binding so images are repainted after enabling/disabling, update test (#68793)

* Move service extension to correct binding so images are repainted after enabling/disabling, update test

* Update binding.dart

Enables custom text selection menus by allowing selectionControls to be passed to TextField et. al.

Fix assert due to VSCode passing in an isolateId as well as the expected args to setPubRootDirectories. (#68721)

This reverts commit ae06c19a.