Again support WDAG in Microsoft Edge. (#15810)
NVDA's support for Windows Defender Application Guard (WDAG) no longer workds as the requirement that the remote WDAG UIA tree be parented into the local tree under the main WDAG window is lon longer true. Thus it is impossible to find the local WDAG window and use this window handle for all WDAG NVDAObjects.
This means that NVA is essentially silent while focus is within a WDAG applcation.
Description of user facing changes
NVDA can again interact with applications such as Microsoft edge when run in Windows Defender Application Guard.
Description of development approach
• When trying to find the window handle for a WDAG UIA element, rather than walking up the ancestry, instead use the currently active window, if it is a WDAG host window and its for the same instance as the UIA element.
• Improve and refactor the part of UIA NVDAObject's findOverlayClasses method that deals with Chrome objects, to match on a UIA framework of 'Chrome', not just of a particular Chrome window class. Code needed to be also reordered so that more specific cases such as documents and lists where looked for first, before the more generic Chrome UIA classes.
