We should support nsaccessibility and iaccessible / whatever on linux.

refs...

https://github.com/iPlug2/iPlug2/blob/master/WDL/wingui/virtwnd-nsaccessibility.mm

https://github.com/iPlug2/iPlug2/blob/master/WDL/wingui/virtwnd-iaccessible.cpp

https://www.youtube.com/watch?v=BqrEv4ApH3U