Add support for the accessibilityAccessKey Prop [Win32 Only]

[chiaramooney]

Add support for the accessibilityAccessKey prop. On Paper, this was only supported for Win32.

Documentation

The prop does not appear to be documented, since it was only implemented for Win32.

Behavior

The accessibilityAccessKey prop is used to specify an access key for a given control. For example, to open the File menu, for which the access key is typically F, the user would press ALT+F. It takes a string value.

The accessibilityAccessKey prop should be used to set the value of the AccessKey attached property. See here for documentation. This is an optional UIA property.

Implementation Plan

We should:

1. Take the accessibilityAccessKey prop and set the UIA AccessKey attached property based on its value.

To Be Clarified

On Paper, this was only supported for Win32. For Fabric, we should discuss if we want this prop to be implemented on Windows as well.