* Fix position of CupertinoContextMenu within Transform.scale (#97896)

* Fix after rebase

This reverts commit 6ddb99e9.

This updates the examples for PhysicalKeyboardKey and LogicalKeyboardKey to use Focus widgets that handle the keys instead of using RawKeyboardListener, since that usually leads people down the wrong path. Updated the See Also and added tests as well. Also exposed the `physicalKey` attribute for `tester.sendKeyEvent`.

This reverts commit 5fd259be.

This reverts commit 5f792ba1.

This PR introduced a new class, ShortcutActivator, and refactored the the definition and lookup system of shortcuts, in order to solve a few issues of the previous algorithm.

- - When I added notification of key events before processing them as text, it made it so that shortcut key bindings like the spacebar would prevent spaces from being inserted into text fields, which is obviously not desirable (and so that change was reverted). At the same time, we do want to make it possible to override key events so that they can do things like intercept a tab key or arrow keys that change the focus.

This PR changes the behavior of the Shortcuts widget so that if it has a shortcut defined, but no action is bound to the intent, then instead of responding that the key is "handled", it responds as if nothing handled it. This allows the engine to continue to process the key as text entry.

This PR includes:

- Modification of the callback type for key handlers to return a KeyEventResult instead of a bool, so that we can return more information (i.e. the extra state of "stop propagation").
- Modification of the ActionDispatcher.invokeAction contract to require that Action.isEnabled return true before calling it. It will now assert if the action isn't enabled when invokeAction is called. This is to allow optimization of the number of calls to isEnabled, since the shortcuts widget now wants to know if the action was enabled before deciding to either handle the key or to return ignored.
- Modification to ShortcutManager.handleKeypress to return KeyEventResult.ignored for keys which don't have an enabled action associated with them.
- Adds an attribute to DoNothingAction that allows it to mark a key as not handled, even though it does have an action associated with it. This will allow disabling of a shortcut for a subtree.

Expose GestureBinding.handlePointerEvent, replacing dispatchEvent as the preferred way to dispatch events (#64846)