Allow desktop windows to be resized & repositioned with a11y services

Voice Access, Switch Access and Talkback have been unable to move or resize desktop windows for a while due to it requiring drag actions,
so as a work around, now there are ways for each a11y service to snap resize and toggle resize desktop windows

Bug: 329550824
Bug: 329549912
Bug: 329549023
Bug: 329547306
Bug: 329547281
Bug: 329540170
Test: manual testing
Test: atest DesktopModeWindowDecorationTests
Flag: EXEMPT a11y changes
Change-Id: Ib63304acb5203937ea5e84b5976b649526ff61f7