1. Add TakeFocus in Windows PDocAccessible.
2. Move RecvTakeFocus into DocAccessibleChildBase so it is used for all platforms.
3. Move TakeFocus into the Accessible base class.
4. Move the IPDL version of TakeFocus into RemoteAccessibleBase so it is used for all plaforms.
5. Make the Windows RemoteAccessible::TakeFocus use the base (IPDL) implementation if the cache is enabled or COM otherwise.
6. Use Accessible::TakeFocus for ATK, Mac, Windows and XPCOM.
Differential Revision: https://phabricator.services.mozilla.com/D130327